# Nerding Out: Why You Shouldn't Worry Too Much About Weight

Oct 13, 2021 at 8:31

No bike review is complete without a weigh-in and most will attract comments arguing whether the weight is acceptable or not. It's easy to see why: weight is a simple, objective metric that's easy to understand and quantify. Lighter is better - simple.

But how much better? After all, saving weight is insanely expensive - most weight-saving upgrades cost several dollars per gram saved. Picking Shimano's XTR drivetrain over SLX, for example, saves 322g but costs almost \$1,000 more (about \$3 per gram).

Within a category (XC bikes, enduro bikes etc.), the gap between a light or a heavy one is about 1kg (2.2lb), and that's about the amount of weight you could save from a typical mid-range bike by throwing money at it. So how much difference does 1kg make?

Climbing

When climbing, the energy required to overcome gravity is equal to the height of the climb times the system weight - the weight of the bike, kit and the rider combined. Let's say an average rider weighs 80kg, plus 5kg of kit and a 15kg bike, which gives a total system weight of 100kg (these are just rough numbers). So adding 1kg to the bike increases the total system weight by 1%. The time taken to complete a climb depends on the power to weight ratio, so adding 1% to the system weight means it will take 1% longer to complete a climb, or 1% more power to maintain the same pace. So for a half-hour climb, it would take 20 seconds longer carrying an extra kilogram at the same power.

What's more, that's an upper limit.

Bike calculator uses an algorithm to model the forces acting on a bike and rider in the real world, including gravity, rolling resistance and air resistance. It's generally considered to be an accurate representation of real-world cycling while eliminating all unwanted variables. If you plug in numbers for an 85kg rider and a 15kg bike, a 10-kilometre course and a 10% grade, it predicts it will take 77.86 minutes. Change the bike weight to 16kg and it will take 78.62 minutes. That's 0.97% more time, very close to the 1% figure you'd expect from power-to-weight alone. But change the gradient to 1% and the extra kilogram adds just 0.38% to the time; on a 0% gradient, the time difference is 0.2%.

So what's going on? On very steep gradients, air resistance and rolling resistance are pretty negligible, so most of your power is going to overcoming gravity. That means lifting 1% more weight takes (almost) 1% more time (or 1% more power). But on a flatter gradient, speeds increase so these other factors take up a bigger share of your power. Aerodynamic drag doesn't depend on weight, so the faster you go the more aerodynamics matter and so the less that weight matters in percentage terms. With rolling resistance, it's more complicated; adding weight will increase rolling resistance but not necessarily in proportion to the system weight. This partly depends on whether tire pressure is increased in proportion to system weight or not. Either way, rolling resistance does increase with weight; this is why Bike Calculator predicts a slightly slower average speed on a flat course with more weight.

The bottom line is that adding 1% to the system weight (about 1 kg) will impact climbing speed by at most 1% on steep climbs, but less on flatter terrain. For typical riding with a mix of flat pedalling and climbing, adding 1% to the system weight might affect the average speed by significantly less than 1%, perhaps closer to 0.5%.

To put that in more context, the difference in power transmitted to the rear wheel can vary by as much as four Watts between different chain lubes at an output power of 250W. That's a 1.6% difference in the power reaching the rear wheel. On a steep climb, speed is proportional to power, so the choice of chain lube could make a bigger difference to climbing speed than a kilogram of extra weight. That makes high-end chain lubes look like a bargain next to carbon components.

In the latest efficiency tests, the times varied by a huge amount (up to 11% between the fastest and the slowest bike), and only a small part of this variation can be explained by differences in weight. Suspension efficiency (pedal bob), drivetrain efficiency and the presence of an idler could make a bigger difference to climbing speed than weight.

Wheel weight has a disproportionate effect on acceleration, but it's still not as big a deal as you might think.

Accelerating

You're probably aware that rotating weight has a greater effect on acceleration compared to non-rotating weight. This is true because when the bike accelerates, the wheel needs to accelerate in the direction of travel (this is called translational acceleration) as well as increasing how fast it's spinning (rotational acceleration). Accelerating anything requires adding kinetic energy to the system, but with a rolling wheel, you have to provide both translational and rotational kinetic energy (usually by pedalling).

If your bike is in a work stand you'll notice it takes energy to turn the cranks just to accelerate the rear wheel up to a high rotational speed - this is the rotational kinetic energy. How much kinetic energy depends on the mass of the wheel: a heavier wheel has more translational and rotational kinetic energy for a given speed.

The energy you apply through pedalling is equal to the power you supply to the pedals (minus all sources of drag), multiplied by the time that power is applied for. So, to get from one speed to a higher speed, you'll need to supply more kinetic energy if the wheels are heavier; this will take more time at a given pedalling power (so slower acceleration).

But how much, exactly?

Because wheels roll, they have a fixed relationship between their translational speed and their rotational speed, and this gives them a fixed relationship between the rotational and translational kinetic energy. The vast majority of the rotational kinetic energy in a bicycle wheel comes from the mass at the outer edge (the rim and tire) - the hub and spokes are pretty negligible. A typical tire weighs about 1kg and a typical rim, about 500g, so for a pair of wheels, that's 3kg of rotating mass that matters.

I've included the relevant equations in the box below, but the gist is that the rotational kinetic energy for this 3kg of mass at the outer edge of the wheel is equal to the translational kinetic energy when the wheel is rolling. That means the rims and tires need twice as much energy to get them rolling at a given speed as the same amount of non-rotating weight on the frame or rider. In other words, the mass of the rim and tire count double in terms of their kinetic energy and therefore have twice as much of an impact on the time taken to accelerate.

The math(s) part:
The rotational kinetic energy of a hoop is given by

E=0.5 x M x R^2 x W^2,

where M is the mass of the hoop (the rim and tire), R is the radius of the wheel and W is the rotational speed (RPM) of the wheel.

But W is given by the translational speed, V (that's the speed you're moving down the trail) divided by the wheel radius, R. So, the rotational kinetic energy can be given by

E=0.5 x M x R^2 x (V/R)^2

E=0.5 x M x V^2

This is the same as the formula for translational kinetic energy. So for a rolling hoop, the rotational kinetic energy equals the translational kinetic energy, so the total energy is just two times the translational kinetic energy.

In other words, every gram in the rim or tire has twice the kinetic energy of a gram that's not rotating. The time taken to accelerate from a standstill to a given speed is given by the kinetic energy required divided by the (net) power supplied by pedalling, so every gram on the wheel has twice as much impact on the time as a non-rotating gram on the frame or rider.

But, remember we're only talking about 3kg here. So for a bike and rider weighing 100kg, the rotational component of the kinetic energy is only about 3% of the translational kinetic energy.

Let's say you swapped to lighter rims which were 200g lighter for the pair. Because this affects both the translational and rotational kinetic energy, the mass counts double, and so it will have the same effect on acceleration as saving 400g from the frame or rider. In other words, it will quicken acceleration by about 0.4% for a 100kg system weight. Hardly a noticeable amount.

What if you went the other way and swapped your 1,000g trail tires for 1,300g DH tires, plus 200g inserts in each wheel, so adding a total of 1kg of rotating weight? For a 100kg system weight, that would slow acceleration by about 2%. If you've noticed that swapping to DH tires feels like it has a bigger effect than this, that's probably down to the extra rolling resistance, not the weight. This suggests that fitting inserts instead of DH tires may be wise in some situations: in either case, the weight isn't noticeable, but the rolling resistance of a stiffer tire is.

One other thing to note is that the rotational kinetic energy of a wheel doesn't depend on its radius, because although a larger radius results in more rotational kinetic energy for a given angular speed (due to higher rotational inertia), the angular speed is lower for a given trail speed, and these two factors cancel out. This means that if you had a 29" wheel/tire that weighed the same as a 27.5" wheel and tire, the acceleration would be the same. Of course, a like-for-like wheel or tire will be heavier in 29", but only by about a hundred grams or so.

Descending

Another reason to want lighter wheels is to do with unsprung mass. This is the weight of the wheels and the other connected components that aren't held up by the suspension. When your wheel hits a bump, it has to accelerate upwards rapidly, then accelerate downwards again as it moves over the bump and the suspension rebounds. How rapidly the wheel accelerates back down is limited by the mass of the wheel but also the stiffness of the suspension spring, which in turn is determined by the sprung mass of the rider, the frame and everything else that is held up by the suspension.

The heavier the wheel, or the softer the spring, the slower it will accelerate downwards on the backside of a bump. The slower the acceleration, the more often it will lose contact with the ground on fast and severe bumps, resulting in less traction and a harsher ride. This is why engineers in all wheeled vehicles refer to the sprung to unsprung mass ratio - the higher the ratio, the better the suspension can perform.

Calculating the unsprung weight of a bike is pretty complicated because it includes a lot of components (wheels, tires, cassette, derailleur, brake calipers, rotors, fork lowers/swingarm etc.) and because the swingarm's contribution to the unsprung mass depends on where the mass is distributed along its length. It can be measured, however, by putting the bike in a stand horizontally, disconnecting the shock and putting the rear wheel on a scale.

Using rough numbers again, the unsprung mass is about 4kg on the rear and about 3kg on the front. Let's say you were to save 100g per wheel by buying lighter wheels - that's about the difference in weight between DT Swiss' EX 1700 and EXC 1200 wheels, which have a cost difference of \$1,964. That would reduce the unsprung mass by 3.3% on the front and 2.5% on the rear. It's hard to quantify how much this will affect suspension performance because that depends so much on the terrain, speed and suspension settings, but I've tested different wheelsets with similar or greater weight differences than this back to back and I can't perceive a difference by feel. It seems to me there are better ways of spending \$1,964.

For big changes in unsprung mass, you'll need to make compromises, not investments. Swapping trail tires for DH tires with inserts might add 500g per wheel (about a 12.5-16% increase in unsprung mass) but the extra cushioning, damping, and ability to run lower pressures in the tires will almost certainly outweigh any downside in terms of suspension performance. Similarly, going from 200mm to 220mm rotors will add 25g for the rotor plus about 25g for the adapter, so 50g per wheel. That's a negligible difference to the unsprung mass (about 1.4%) but a noticeable (10%) increase in brake power which could reduce arm pump and increase enjoyment and speed.

While some world cup racers run carbon frames and Ti bolts, Jack Reading once raced a Nicolai with lead weights added, bringing the total bike weight up to around 23kg / 50lbs

Could a heavier frame be a good thing when descending?
If making the wheels lighter is impractical, what about deliberately increasing the sprung mass of the frame in order to increase the sprung to unsprung mass ratio and thereby improve the suspension performance? I investigated this at my previous employer, and while the results were inconclusive, the bike definitely felt calmer and less harsh with 3kg of lead strapped to the frame.

At the time. I put that down to the increase in the sprung to unsprung mass ratio. But now I realise a more relevant factor is the ratio of the rigid sprung mass (the frame and other rigidly connected components) to the total sprung mass (the frame plus the rider).

Because the rigid sprung mass of a bike is so light (around 9kg), it accelerates upward rapidly when the bike hits a bump. This acceleration continues until the rider's bodyweight gets involved, which is only after the bike is moving upward towards him/her. This disconnect is what causes MTB suspension to perform so poorly compared to motorcycle suspension; the suspension needs to be stiff enough to support the total sprung mass of the bike plus rider (perhaps around 90kg), but when the bike first hits the bump, the rider is too loosely connected to the frame to provide much resistance. So the 9kg rigid sprung mass starts to accelerate upwards rapidly, without much suspension movement, until this lag is overcome and the rider starts to accelerate with the frame and create enough resistance to compress the suspension. Increasing the mass of the frame reduces this initial acceleration and forces the suspension to move earlier, and so decreases vibration experienced by the rider. This is why e-bikes are far more comfortable to ride on rough terrain, even when running less sag.

I'm not necessarily saying heavier bikes are better overall when descending - both Jack Reading and the Santa Cruz Syndicate experimented with adding weight to their race bikes, but as far as I know, neither stuck with it - but I am saying there are tangible benefits to heavier frames when going downhill. I certainly wouldn't stress about having a lighter downhill bike, unless you're carrying it to the top!

If Troy Brosnan, at 75kg, benefits from 220mm rotors front and rear, maybe you would too.

Don't miss out

One common argument is that, yes, a few grams here or there isn't much on its own, but saving weight where you can throughout the bike adds up to a noticeable saving. This may be true, but allowing for burlier parts in your weight budget adds up to big benefits, too. For example, bigger tires offer more grip and cushioning, bigger brakes reduce fatigue and allow you to stop later, stiffer forks can improve suspension performance through chunky terrain. These factors in isolation might not make much difference, but between them, they create a more confidence-inspiring ride.

The relationship between bike weight and speed on technical climbs is more complicated.

Some good counter-arguements

My overarching argument here is that the importance of weight is overblown, largely because the weight of the bike is pretty small compared to the weight of the rider, so an extra kilogram on the bike might add only 1% to the amount of weight you have to shift up and down hills. But there are some exceptions where this logic doesn't apply. In particular, when bunnyhopping, pumping, carrying your bike, or technical climbs involving manoeuvring the bike up and over obstacles; a kilogram on the bike may count more than a kilogram on the rider here.

I've also been assuming throughout this thought experiment that the system weight is about 100kg, but of course, if you're a lot lighter any additional weight will have a bigger effect.

To conclude, I'm not saying that a 16kg bike is indistinguishable from a 10kg bike, or that lightness isn't a good thing. I am saying that when you run the numbers the benefits of saving a realistic amount of weight are smaller than you might think, while the advantages of heavier components can be far more tangible in terms of descending performance, not to mention reliability and cost.

Author Info:

Member since Dec 29, 2014
299 articles

• 992 8
ever since i switched to carbon, my bike is now much easier to hike down all the technical features on my local trails!
• 105 2
• 29 1
@Mugen: Sadly I missed the beginning of the outsideCEO party, my inner troll is sad. Can someone please post a link to the begining of the story, thank you. (rick roll and shady url accepted)
• 120 1
@fracasnoxteam: So basically on Monday, an account by the name of OutsideCEO posted on a couple of links. The account holder must have done research on the real CEO, and posted as if he was the real CEO but in humorous ways. Essentially stating his love for gravel bikes. self driving cars, and sending PB'ers more unwanted adverts that they never asked for.

Then he posted on this link www.pinkbike.com/news/video-jack-moir-celebrates-his-ews-title-with-a-metal-monday-mash-up.html, and was promptly removed within an hour or so.

Community members started calling out certain PB Staff asking why he got banned, and what rules he broke since nothing he said was bad, or inappropriate by any means. Hence #restoreOutsideCEO.

Well, sounds like PB listened behind the scenes, and unbanned the account that now uses the name NotOutsideCEO
• 29 0
@fracasnoxteam: I also missed out on the real outsideCEO fun, so I went through notoutsideCEO's comment history this morning, learning all about his love of gravel bikes and subscription plans. One of the better troll accounts on pinkbike, they are losing out by deleting his comments, it's all in good fun.
• 8 1
@h20-50: thank you very much. Was busy dealing with stolen bike, lot to do.... So #restorerealoutsideCEO !!!
• 242 3
@h20-50: Thank you for the support my German friend. The whole community here has really done a lot for me these last few days. My own CTO turned his back on me and banned my account - he said it was for my own good, that my delicate sensibilities could not handle the comment section...that my subscription models have been TOO successful, that I've made TOO much money...that I am no longer in touch with REAL cyclists. BALONEY...everyone here drives a Model X, to WholeFoods while buying the original CryptoPunk at auction right!?!?

Well either way, out of nowhere swoops in the hero I never knew I needed...Brian Park (he's getting a big raise for the BTW - assuming HR lets me do it!), who restored my account under this pseudonym. Please help me keep a low profile so those Downhillers in IT don't come down on me again (pun intended!).

Finally regarding weight...if you're really that worried about it, might be time to get a gravel bike!

Be safe be well,
Incognito Robin
• 12 0
@fracasnoxteam: Dude, I hope you get that bike back. Fugging hate thieves! Scum
• 20 0
@h20-50: I really hope it actually is the Outside CEO just trolling everyone - his staff included.
• 123 0
What this article fails to recognize are the real and quantifiable gains when your buddy picks up your bike at the trailhead and is amazed how much lighter it is than his bike.
• 22 1
@tkrug: Ha! I was thinking the same thing. That would be the ultimate troll.

Also, he needs an Outside+ tag on his profile, but I think they’ve removed those because people were voting them down into oblivion, for the sole crime of existing.
• 34 74
hamncheez (Oct 20, 2021 at 8:01) (Below Threshold)
@Philthy503: How many times do I have to say it- any non-alloy bike over \$3000 is not designed nor intended to maximize trail performance. Its designed to maximize parking lot performance.

You don't get a Yeti over a GG because it makes you faster, you get it because it increases you social capital amongst your other overweight middle aged peer group.
• 2 31
@h20-50: ... and we care because??

Don't let Outside magazine use drama to attract readers and increase clicks.
• 5 81
@notoutsideceo: Hey Robin, dude, it was funny in the begnning, but not anymore, just saying.
• 24 0
@hamncheez: I'd recommend trying these bikes before you trash on em
• 11 0
I think the intent of this article is for us to not worry about he weight of E-bikes. As the weight goes up, it does become harder to handle the bike and keep it going where you want it.
• 27 2
@nurseben: got your panties on too tight there bro? Go up a size, maybe you won’t be a complete asshat if they fit right.
• 23 2
@BoyMan: Come on everyone its a joke. I myself had several carbon framed bikes until I got an even more pretentious titanium bike.

I've actually cracked several alloy bikes, and I'm not a super amazing rider. I think that aluminum's fatigue life is a real issue for bikes.

But two of the cracked frames were Konas, so that could skew the data.
• 1 19
@h20-50: Nah, I just don't care about the corporatization coop of social media.

But I do agree that folks focus on bike weight to their detriment.
• 10 2
@abzillah: I have a 54lb ebike and it is so much more planted but dang it’s hard to control once it gets moving. Don’t get me wrong I love it for climbing and on chucky chunder I like it but when it comes to steep whoa nelly it’s a beast to wrangle.
• 3 0
@notoutsideceo: We have to make this big enough to start getting in to the slack randoms!
• 6 0
Seems like a well timed article coinciding with the shutdown of carbon manufacturing in Vietnam. We should all be happy with the aluminum frames we can purchase now that we don’t have to worry about the 1kg extra weight.
• 5 4
@Mugen: weight snobs and mountain bikes is the equivalent to people with poor vision shopping for the best HD tv.
• 11 1
The industry wants you to think weight isn't a big deal because they are pumping out 38lb enduro bikes....
• 4 4
• 2 0
@alexlavallee: not mis-lead-ing because not science, just some matter to think about it.
• 1 0
you could just toss it down instead of carrying it, since it's so light....it'd float like a leaf....
• 145 1
@Seb Stott fantastic article. While making it quite short you managed to cover all the main topics.

There is one aspect of the weight/price/strength compromise which doesn't seem to be adressed at all in the bike industry, it's the relationship between rider weight and parts strength.
For example, I'm heavy and when riding XC I can't use XC wheels, and to get a bike which won't break/flex too much, I need to look in the 130-150mm category.

On the other hand, my gf is 50kg and the main thing that is swappable to save weight is wheels and tires. Because she's not going to replace a Lyrik with a Pike/34 to save a few grams... or cranks... etc.
In the end her bike weight / system weight ratio is 14/64=22%, when mine is 17/112=15%.

That's a 7% difference, a lot more than the small numbers mentioned in the article.
• 56 1
Thanks!

Yeah, that's a good point and it goes hand in hand with the disproportionate sizing problems which very tall and short riders face (same crank length, travel, BB height, chainstay length, and virtually the same stack height for 160 or 200cm riders). Light riders often have overbuilt bikes and heavy riders often have underbuilt ones. For a trail bike, you can often up-spec components if you're heavy (fit DH wheels, tires, brakes or a burlier fork), or maybe fit XC parts to a trail bike if you're really light.

For XC or DH though, there's nowhere more extreme to go. If Tanhee Seagrave is better off on the DH casing than SuperGravity tyre, then perhaps someone much heavier like Wyn Masters would benefit from a tyre that weighed 10-20% more?
• 24 0
I mentioned years ago that it would make a ton of sense if manufacturers specced lighter/heavier components depending on frame size. Size is only an approximation for rider weight, obviously, but the correlation is still fairly strong.

With bikes in the 5-15k price range nowadays, that little bit of effort is certainly not too much to ask.
• 2 0
@seb-stott: Hi, some of the comments below mention people conflating lighter tyres with lower rolling resistance. Is there anyway something like this could be calculated for future tyre reviews. As in the power it takes to go 20km/h on a flat tarmac road
• 5 0
@briain: it’s not all inclusive but it is a start www.bicyclerollingresistance.com/mtb-reviews
• 11 0
Also bike weight should be proportional to rider weight. Heavier riders need stronger bikes. Strength usually comes at the cost of weight - strong, cheap, light : pick 2... This assumes both riders are riding equally as hard.

Therefore comparing bike weights is irrelevant unless rider weight is also considered.

I'm ~100kg kitted up and my FS trail bike is 41lb (18.6kg) including tools and full bottle and coils both ends. This equates to a 26.6lb bike for someone that is 65kg.
• 6 1
also @uuno - I think it might be worse than you state, regarding your bike weight:system weight ratio. Yours at 15% vs GF at 21%, thats 50 percent higher for her.
Assuming strength is *roughly* proportional to body mass (which it will be roughly unless you are a skinny bloke with a huge beer belly) she is having to work 50% harder to move the bike around dynamically on the trail.
Although a big long climb, and she will reap the benefits, as Seb's article indicates.
• 2 0
@DHhack: Nice, didn't know that existed.
• 1 0
@Ttimer: I ride the biggest size bike the brand offers and i'm 65kg.
• 1 0
Agreed. I weigh 54kg, and from my XC bike at 18% of my weight to my enduro bike at 29% of my weight it is a significantly noticeable difference. For light folks, we often have to face the heavy burden of bike or wallet. Hopping and moving the enduro bike at slower speeds is tough. That being said at high speeds it is very stable.
• 9 0
@seb-stott: good article! My bikes are generally xxl and built to take a beating, aka heavy.

This has confirmed what I thought, my bikes weight compared to by buddies bikes just doesn't seem to make that much difference up or down hill
• 1 1
@Ttimer: I feel you on this. I do think there would be some hurt feelings because this could imply that smaller riders (more typically women) don't ride as hard. I think it might be better to offer a team build and a trail build for each model.
• 2 0
I'm with you, I look at bike weight more in relation to rider weight than focusing on the bike weight. I'm 205-210lbs and ride by all accounts heavy bikes, boyh my bikes are alloy and are about 35-36lbs. But proportionally the are the same as a 155lb rider on a 27lb bike (~17%). I personally like the way a heavier bike feels more stable on the descents and that it worth the tradeoff on the uphills.
• 5 0
@lefthandohvhater: It is a unique scenario where I (as a lighter rider) can ride as hard as most, and rail bikes, but can also get away with less suspension. The D***C*****y segment is great for us who need lighter bikes, but want good geo and can still rail the trails.
• 1 1
@Ttimer: And then people would buy two models of the same bike, one small and one large, swap out the light components from the small to the large bike and resell the small bike with the heavy parts. The price/tier model can only be broken laterally by buying from a low overhead brand. I've noticed buying entry level bikes for my kids that bike brands really just don't give a shit and spec lead pipes and pot metal where they could easily save a ton of weight for cheap for a more enjoyable bike and create a rider for life the process. But, nope.
• 12 2
@seb-stott:

Feature Seb Scott more.

Also in the PB podcast. Look I like the cast of characters on the podcast and it appears that they work hard on the content ideas and the firmat. BUT it puts me to sleep, literally. My theory: I’m a bike nerd, I like the deep dives into MTB topics. Often times the setup and concept is good on the podcast, but the actual discussion is shallow and a bit lame. Add in Seb Scott…let him go deep. You have a better podcast. For the model of a great podcast I highly recommend you listen to the now defunct original “MTB Podcast” that was great content. They made meaningful deep dives in the way Seb does in his articles.
• 8 1
@Jpzeroday: Yeah can we get a "Nerd Alert" pinkbike podcast with Seb? The more general discussion is not as interesting to me. I still love the podcast anyway!
• 5 0
@Jpzeroday: NSMB is where you need to look. They go deep. Seb would fit right in.
• 1 0
@fartymarty: Featuring chris porter on a podcast? SOLD! Bikes and big ideas is another good one for anyone curious!
• 4 0
Good point, but what about all those 8 year old boys ripping their 14kg bikes at bikeparks harder then most IT dads on their carbon beauties? They get like 40% bike to rider ratio. Guess they are like bumblebees, they fly against science and common sense.
• 4 0
@lkubica: you tend to ride different when it doesn't hurt two seconds after a crash LOL
• 9 0
Have you considered the relationship between rider weight and gf strength? Please consider swapping your 50kg XC gf for an Enduro gf if you're nailing the technical sections hard.
• 1 0
@lefthandohvhater: and it was a 2 part podcast... Enjoy.
• 7 0
@briain: Rolling resistance is a very important metric (more so than weight in most cases) but unlike weight, it's very hard to measure.

This website (linked below) is a good resource that measures rolling resistance on a drum. Problem is, the convex drum probably increases rolling resistance compared to a flat road surface and the wheel in these tests is passive, whereas a powered rear wheel may behave differently due to the propulsive friction at the contact patch. They also don't properly model the effect of bumps and how they interact with the suspension and the rider.

I've attempted to rank tires on rolling resistance in the past using roll down tests and climbing to power but it's hard to get repeatable results in the real world (a breath of wind can affect the times too much). Maybe an indoor version would be ideal.

www.bicyclerollingresistance.com
• 1 0
@Jpzeroday: @fartymarty @lefthandohvhater - earlier episodes of the bikeradar podcast have plenty of seb nerding out (mtb tech talks IIRC), and there's a chris porter interview in there too somewhere
• 1 0
@hungrymonkey: the SS / CP Bike Radar podcast was great. I've listened to it a few times. I love deep nerd podcasts.
• 2 0
@seb-stott: 'Rolling resistance is a very important metric (more so than weight in most cases) but unlike weight, it's very hard to measure."

100% agree. I'm running a Tough Trail Boss on my HT and it rolls really well despite the weight (nearly 1100g for a 2.25x29). I would rather ride it on road than a gripper lighter tyre.
• 1 1
@fartymarty: I'm 66kg and 6 foot tall. Right now I am on a 30.8 lb (14kg) bike but I wish it was lighter but I am trying to make peace with the fact there is no chance of that happening. I am actually considering getting rid of my dropper post and reducing the number of gears on the bike as these are low-cost ways of making the bike lighter, it's already full XT with a pike and EXO casings. I'm don't sit much anyway. I can always take a water break and raise the seatpost

I can't live with the super short travel or XC geometry of the current light weight options, the specialized epic evo was close-ish. Maybe when downcountry (lol) gets into more of a swing there will be a better option for me. Fingers crossed.

Even worse, I am a 27.5 guy because I can't figure out how to not buzz my ass tucking off jumps on 29ers so my options are crazy limited, previous bmx freestyle life has made my muscle memory non-conformist
• 2 0
Really like where you are going with this. I'd go a step further in saying it's frustrating to see \$10K size XL bikes with a DT370 rear hub at best, 150mm dropper and a narrow Q-factor. Once you buy that super pricey bike you end up swapping out parts! But hey, they can't supply enough bikes to meet demand as it is so what's the incentive?
• 1 0
@Ttimer: there are plenty of overweight short people out there!
• 2 0
@jlauteam1: definitely a lose lose situation. lighter drive trains are possible with less gears if you have the legs for it. Dropping to a 36t cassette saves a ton of weight over 50s.
• 1 0
In my ideal dreamworld there would be a 3 speed cassette/derailleur that covered 14T-24T-36T.
I realize I am a special use case where I just want a light, shortish travel, smallish wheel bike with halfway-to-gravity-bike geometry and minimalist features. The SC 5010 was as close as I could find and it's been great. Just haven't taken the knife to it yet to see how awkward and personalized I can make it lol.
• 3 1
Thanks to a excessive and eclectic quiver of bikes, I can tell you that my size medium 42lb 29er ebike is easier to throw around than my 32lbs size large mid travel 27.5 bike. It's shorter and has a steeper HA and the weight difference doesn't really seem to matter. My P.Slope is easier than the ebike, it's 28lbs and shorter yet again. My NS Decade is only 23 lbs, with similar geo to the P.Slope (relatively) though higher BB and it's hard to notice it's even there.

But the easiest to throw around is the 21" TT BMX, which is very heavy for it's small size... 27.33 lbs. It's also the shortest in the quiver.

One note: the RAD across the BMX, DJ, and slopestyle bike is very similar, within half an inch.

My son has been riding since 18 months and five bikes later, I can tell you weight really only matters when it gets extreme. Geometry and fit always matter much more.
• 2 0
@piotrv: besides a bunny hop, my 250 2 stroke motocross bike isn’t that much harder to throw around than a 29er lol.
• 2 0
@fartymarty: alternative strategy is to start exercising too much, lose heaps of weight off formerly flabby bits, lose lean muscle mass too. Then next time you ride the ruff stuff, your bike is now proportionately heavier, so a) you get shaken around real bad and b) you plan on buying new light weight bike to compensate. Lesson - eat more pies and keep riding the old bike.......
• 1 0
@RustyNZ: LOL, I'm eating enough pies, burgers and pizza for both of us.
• 1 0
@seb-stott: yep, and I have no idea why even easy solutions aren't applied, like wheel manufacturers making a set with 28 spokes front and 32 rear. Isn't it obvious we can save weight on the front which suffers less abuse?

I have one question about the stack height : why is it generally so low on DH bikes?

All measures from largest size (all XL except old Rage which is L, and Megatower XXL) :
27" Rage 611mm, new 29" Rage 638mm, Sender CF 29" 636mm, Sender Al 27" 625mm, V10 29" 641mm, Session 639mm, Demo 629mm.
Always lower than the enduro models :
Torque 27,5" 645mm, new spindrift 660mm, Nomad 648mm, Megatower 666mm, S Enduro 638mm.

Is it just that dual crown make a lower stack possible, so designers just make it as low as possible and expect people to use >50mm riser bars if tall?
Or does sag explain this? (if 20% front and 30% rear, the rear drops 20mm more than the front on a 200mm bike vs 15mm for a 150mm bike, and this difference is even bigger if we take into account that the front sag is less vertical than the rear sag).
• 2 0
@ultimatist: I already got the real deal Enduro gf, just in the very compact package
• 78 3
>Skims article
>Sees some sort of physics calculations
>*sighs*
>Shuffles over to light the Bat-signal for all the PB engineers..

In all seriousness though, lighter rubber (when applicable) absolutely transforms my trail bike. Some of the most fun I've had on my trail bike was running 2.4 Ikons F/R. Crazy quick, and surprisingly capable!
• 24 1
Lighter, or just better rolling?
• 13 0
@lkubica: Both. ~200g lighter per tire. Smaller knobs rolled very well. I think the thing that surprised me was how hard I was able to push them before breaking traction. I was expecting ice cubes, but that wasn't the case at all.
• 5 0
Same here. I've run my Minion SS 2.3 tyres all year, only when it's really muddy (like now) I switched to chunkier tyres.
• 19 0
Tire selected for the terrain and application is 100% important.
• 18 2
@mikealive: I know, but you don't know which feature has bigger influence on this feeling. Typically people tend to say "I bought lighter tires and I immediately felt the difference thus weight matters". But they did not change only weight so the cannot draw such conclusions. The same was with 26, 27.5, 29 wheels, like 29er rides better than my old 26 - yeah, but you compare totally different bikes, with different everything. People have tendency to oversimplify and draw false conclusions.
• 12 2
Switching to a DH rear tyre on my hardtail transformed it; I can now ride so much harder and in much more comfort too.
• 3 1
@lkubica: I said it was both the lighter weight (decreased rotational mass) AND the smoother rolling tread. I don't think it's an issue of knowing "which feature has a bigger influence", or at least I wasn't making an argument to that point.
• 2 6
chakaping FL (Oct 20, 2021 at 1:11) (Below Threshold)
Could have done with a TL;DR summary TBF
• 13 2
@mikealive: Yeah switching to faster rolling tires can have a huge influence on speed. Generally lighter tires will be faster rolling because of intended use (tires designed more for XC will be ligher, harder compound and have smaller knobs in general) and simply because fewer sidewall layers mean a more supple tire and so less energy is lost as the casing deformed to the ground as it rolls. Obviously, the lighter weight will help when climbing too, but the lower rolling resistance is likely the bigger factor in most situations.
• 19 1
@seb-stott: I think people are missing what I said in my initial comment--my point is not about all out speed, or even primarily speed focused. Quicker rolling due to tread, yes, absolutely. But there is an *entirely different feel* when you knock ~200g a wheel off the bike AND it rolls easier, hence "...absolutely transforms my trail bike". You can pick up the front end and pop the bike all over the place--is that only because it rolls smoother? Or does knocking almost a half pound per wheel off the bike have something to do with it?

That's why I lit the PB engineer signal. I'm not an engineer. I am sharing personal experience. Anyone who has run Minions and Ikons in the same season feel free to share your experiences here.
• 5 0
I think it boils down to run the fastest rolling tyre you can enjoy without compromising grip. If you're using brakes to manage speed on your trails than more grip is important. Sure with my EXO set up I'm not as quick at Bike Park Wales or over short sections of gnar, but my overall times are better, and getting to the top easier and faster means more time and energy to practice going back down.
• 6 0
@dodgems: I firmly believe that Minion SS with a DH casing is the most underrated tyre around. I run it as a rear on all my bikes bar the DJ (because I can’t find it in 26” anymore). Very rarely do I need to switch tyres to something with more centre tread.
• 1 1
I switched from a DHR2 Exo+ to a Michelin DH34 on the front of my Dartmoor Hornet, a weight gain of >300 grams.
It was a hopeless pig to bring uphill and accelerate, but a monster on the way down.
It blew my mind not only on the straight line gnar, but also in corners, holding lines like never before. Total confidence booster at 0.9 bar (yes,sidewalls were that stiff).
Once worn, I put on an Exo+ Assegai... just for a ride, immediately replaced with a DH casing one.
And I have to say, while an awesome and faster rolling tyre, it lacks the ferocious, stubborn, smash-it-all feel of the DH34, which I think is due to its sheer weight and rotational inertia.
• 6 3
It's all about the tread type. I changed from Assegai DH casing to Assegai Exo+ (both Maxxgrip rubber) in order to "get a lighter feeling front but maintain the same level of grip". Or that was my intention but guess what, it still rolls and accelerates as bad as the DH casing Assegai. Instead I got a tire that is more prone to punctures, and has a less stable casing forcing me to run higher pressures. The 200g weight saving did diddly squat to the feeling on the trail.
• 4 0
You just have to ride the trails round here after some rain to know what heavier tyres feel like... Add some mud, and they're definitely harder to manual, slower to accelerate, and generally far less fun. Yes of course there's far more drag too, but heavier tyres are probably draggier even without mud. The other difference is how much harder the bike is to move around trail obstacles etc, even if the 75kg lump up top stays on the same line.
• 2 0
@Tasso75: that’s the gyroscopic benefit of rotating mass that I harp on about. I think it’s a huge benefit of a heavier rim and tyre combo for my riding. I don’t have to deal with a huge amount of mud for my riding, or my philosophy may be different. Fast rolling, wide tyres with DH casings at high pressures, on aluminium rims gives me a superb experience. A light wheel and tyre combo might benefit my climbing or (attempted) jibbing, but I can’t sacrifice the high speed stability right now.
• 1 0
edit: woops replied to wrong comment
• 1 0
@chakaping: Check the last section - Some good counter-arguements
• 2 0
@Afterschoolsports: This. We seldom deal with thick mud around here, but rocks -especially limestone shards- are aplenty, hence the need for stability.
• 6 2
Rotational mass is the very first thing I target with new bikes, it makes such a big difference. This is even more important on newer 1x platforms that can ship with 600g+ cassettes. My two new recent bikes had those cassettes and I dropped nearly 1lb just by upgrading rear wheel/cassette combo.

On my 150mm bike, swapping out the 2.6" tires for XC tires really woke the bike up, felt much more lively. This has inspired me to go after carbon rims.
• 3 1
And this is why my 39lb 2021 Norco Range with Continentals is the best climbing bike I’ve ever owned. We are too accustomed to 40lb bikes from 2001. Those pedalled poorly because of suspension and geometry.
• 3 0
@mikealive: I ran Vittoria Barzo front and rear on my hardtail this season, and I thought I was going to die.
They are super fast, especially noticeable when accelerating, but there is less than zero grip in turns, especially loose over hard.
So damn sketchy, had a few very close calls due to a lack of grip, never running XC tires again.
• 2 0
@Tasso75: Mostly how well damped the carcass is, that really helps, doesn't "ping" off every little rock and root in your path.
DH34 also has absurdly grippy rubber, so much cornering grip.
Currently have DH casing Assegais front and rear, while they have very good grip in most situations, they can't match the absurd grip of my old DH34 tires.
Might be better in muddier conditions, but I don't ride much in mud, so not very relevant for me.
• 2 0
You'd be surprised by how quickly Cross Kings rolls and grips. Puncture is somewthat debatable, but tubeless is golden. ~650g for 26x2.3
• 1 0
@dodgems: front and back? Or just back?
• 22 3
I don't over think this stuff but I never buy into the argument that a bike is only a minor fraction of the overall weight of the system argument. It's a tool where we are applying forces and leverage. For example, a tennis racket weighs probably 1% of the total weight (racket + user)... But swing a racket that weights 2X as much (still less than 1%) and you'll be degrading your performance in a pretty obvious and impactful way.

Bike terrain and demands are dynamic - depending on the move, having a bike that weighs 10% more might require 100% more effort to see realized. So I think the linear assumption of weight to effort (energy) is too simplistic. Like most things, it depends.
• 4 5
@CarlMega: That racket is a fairly simplistic comparison. On a bike, the entire system weight includes the weight of the rider. I think in your comparison, you'd be better off comparing the impact the weight of a heavier racket has on the grip your shoes provide on the court and your ability to accelerate into motion to hit a ball across the court from you. Alee at Cycling About also covers weight fairly extensively and has done his own experiments with weight that align fairly well with the theoretical numbers presented here. The problem is that we are conditioned to believe lighter is faster after years of the industry selling us that concept and therefore we placebo'd our speed. It's similar to the revelations that are coming out in both road and mountain biking about how fatter tires are lower rolling resistance, faster over distance, and provide more comfort. Speak to a roadie from 20 years ago and they'll believe that if you aren't getting hammered to death by 20mm wide tires inflated to 100psi on as stiff a frame as you can find that you're doing it wrong.
• 2 0
@mikealive: same pressure as previous tires? crazy quick proven by a clock, or just feel? (because often chattery or sketchy can seem quicker but not be quicker)
• 5 0
@justinfoil: I'm confused why people who have read my actual words "...absolutely transforms my trail bike." and "Some of the most fun I've had on my trail bike..." are asking about a clock? My statement was qualitative, not quantitative. "Crazy quick" as in movement/handling of the bike, if that helps clarify it for the third time.
• 2 0
@CarlMega: good point - to sling the bike about, pop over stuff, avoid rocks, manual is all easier with a light bike. And those are all things that either make it more fun or less tiring. For route 1 plough through style, heavy may be better, I guess
• 2 2
@mikealive: Maybe because you're commenting on an article that's all about objective improvements: 1% less weight means 1% less power needed or 1% faster, for the specific situation. We can only assume when you say "quick" in this context, you mean it as "go [objectively] faster".

Everything you said is completely subjective. I find the opposite: heaver tires (which also allow less pressure) tend to stick to the ground more (when well damped), giving me more traction in all acceleration events: straight line acceleration, braking, and when changing direction; meaning it's "crazy quick" and "the most fun", for me.
• 4 0
@CarlMega: especially because you are accelerating your bike not once, but with every pedal stroke again and again. Think of a steep out of saddle climb. Assuming constant velocity just doesnt work here.
• 3 0
@justinfoil: So that's your argument? To prove my exact point? Interesting..

Where to even begin. Ikons 200g lighter than Minions.. subjective? Wheels that now weigh ~half pound less each and also roll quicker.. subjective? I commented what I did on this article because it was counter to what the article seems to be suggesting--that a little weight here and there is only a small percentage, *and thus not a very big deal*. Would that be an accurate simplification of the thesis of the article? Right, so I stated that I was pleasantly surprised at how going to a lighter tire with smoother tread (re: must know what the Ikon tread looks like) made the bike "quicker", changed the bike, and was fun to ride. I didn't say it was "better" than anything, but it does suggest that even small percentages can have a big difference in feel for a bike. So you know the math calculations in the article are great and all, but what was being missed was real world application. Tire tread AND wheel weight have an affect on how a bike rides. Thank you for proving that point by sharing your anecdote. How or why this became a pissing contest baffles me. I never claimed that Ikons were "better" per se, I said they were 'fun' and 'quick' on my trail bike, enough so to cause me surprise.

So your response is to say you like a different tire and have more fun that way?? Neat. Go off I guess. I don't see where the debate is. People mad that I didn't time myself? Ok. I bunny hopped off the small stuff and jibbed all over the trail and had a blast, bike felt way different, but I guess that counts for nothing. A quantifiable metric like wheels that are a half pound lighter is all placebo I suppose, because math article is smart. Got it.
• 3 1
@CarlMega: That would make sense if you were swinging your bike around with your arms... wait...
• 5 1
@CarlMega: yes, I've been saying this forever. We experience the weight of the bike at our hands and feet. Any time we maneuver the bike the weight is at our extremities.
• 4 3
@mikealive: What pissing contest? You ambiguously commented about differences caused by weight on an article about objective measurable differences caused by weight, and got mad when people asked if you took objective measurements. Turned out you didn't and were talking about subjective "feels", despite the premise of the article not being at all about "feeling" fast.

Everyone knows that changing weight will make things feel different, just like changing tire pressure will make things feel different. But for the longest time everyone thought high pressure meant fast, and it turns out that was pretty wrong. Seb is showing that the same thing might apply to weight: lighter is not always as big an improvement as once thought, at least for the value of energy used to increase elevation (arguably the most important part of climbing, though of course not the only part).
• 2 2
@justinfoil: I don't understand, honestly. Are you the comment police? Are you the one who decides that because article is about X that every comment can only be about X? It's odd to me, but wear that badge with pride I guess. Sorry I was too 'ambiguous' for you bro, lol. Plenty of other people seem to understand what I was saying though, so maybe it's you?

I didn't 'get mad' when people asked if I took objective measurements. I was confused--big difference. But I've already stated that my original comment was qualitative, not quantitative, in fact I've clarified this to you, specifically. I also corrected you when you claimed the entirety of my original comment was purely subjective. But here you are beating dead horses. Did you want an apology that my comment wasn't what *you* thought it should have been? Ok, I apologize. Next time I'll check with you before sharing my personal experiences.
• 2 0
Try Vittoria Mezcals, rolls even better and grips way better ( i tried both tires for fast trailriding and the Mezcal is a beast)
• 1 0
@mikealive: "mikealive (Oct 20, 2021 at 12:22) @justinfoil: I'm confused why people who have read my actual words are asking about a clock?"

Not policing anything. I have no pull here beyond a negative props (which I did not put on any of your comments). Just trying to explain why people are doing the thing that confuses you.
• 1 0
@justinfoil: First of all if you're going to quote me, use the actual full quote. Otherwise you need to use an ellipsis to indicate you have left words out that may add further context. The FULL context:

@justinfoil: "I'm confused why people who have read my actual words "...absolutely transforms my trail bike." and "Some of the most fun I've had on my trail bike..." are asking about a clock?"

The words I used all the way in the beginning of this thread in my original comment should have, I thought, indicated that I was making a qualitative statement. I have indicated this was the case another two times in this thread, but I'm beginning to think a few people do not understand the difference between the qualitative and quantitative in nature. User Ikubica had a valid question in if the differences I noticed might be due primarily to tread pattern, and I clarified. Seb, the author of this article, echoed some of Ikubica's questions, and I clarified my point further for him, with "I think people are missing what I said in my initial comment--my point is not about all out speed, or even primarily speed focused. Quicker rolling due to tread, yes, absolutely. But there is an *entirely different feel* when you knock ~200g a wheel off the bike AND it rolls easier, hence "...absolutely transforms my trail bike". You can pick up the front end and pop the bike all over the place...". Seb's questions were even further confounding because the title of the article isn't 'Why bike weight doesn't slow you down', the title is "Nerding out: Why you shouldn't worry too much about weight". So even in the title it doesn't state that this is a timing/speed-based argument Seb is making. It was after alllll that where you came in and asked:

justinfoil (Oct 20, 2021 at 11:5
@mikealive: same pressure as previous tires? crazy quick proven by a clock, or just feel? (because often chattery or sketchy can seem quicker but not be quicker)

Can you see why I would be confused? How are people commenting in this thread when they apparently cannot read? I had already clarified what I was saying a few times before you even came in to ask your questions. Questions that appeared to still be missing the entire point of my initial comment. *Then* you tell me that you're asking those questions due to the nature of the article...which would seem to imply that because the article uses some 'Bill Nye' calculations to support a hypothesis, that I cannot make a comment that does not align with the article, or one that is not quantitative in nature. Even though it had already been clarified that the tires were *objectively* lighter, and *objectively* faster rolling, which common sense would tell anyone with a functioning frontal cortex will have an impact on how the bike feels and handles. This is what I was commenting on.

The next two major comments below mine are saying essentially the same thing as I was--that weight DOES have a big impact on how a bike rides and handles, timing devices be damned. And the truly hilarious thing about all this is I can go through the rest of the comments on this article and see you making the same misguided replies elsewhere in other threads. Yet you come back 4 days after the fact to gaslight me and tell me 'oh I was just trying to give you an answer because you said you were confused'. Nah dude. I don't buy it. Either you're Seb's cousin, or you see some poorly applied physics calculations and think 'this has to be right' and stroll into the comments section with police nightstick in hand. I don't downvote based on conversations either, so no internet points hate from me. But I can see you getting downed on the other threads. Do you think that might be due to *you* missing the point of what others are saying?
• 1 0
@mikealive: "So even in the title it doesn't state that this is a timing/speed-based argument Seb is making."

Umm, talking about reading whole comments/stories. If you read the whole story, it's pretty clear it's about simple things like relative power needed to lift a given weight up a given height. Pretty clearly not about how the ride feels.
• 1 0
@justinfoil: *sigh* My whole response, and that's all you got? A misrepresenting of what I said? Yeesh.

In the title, THE TITLE. Not the article. I was speaking specifically about the titular claim 'why people shouldn't worry too much about weight'. But that said--for what feels like the fourteenth time, *why* does it matter again? I thought you said you weren't the comment police? Oh that's right, I'm talking to PB comment section Barney Fife. And because the article was about measurements and calculations, a person cannot comment anything to the contrary. Your circular logic is astounding, truly.
• 3 0
@mikealive: and @justinfoil: enough please. This isn't Twitter, it doesn't really matter. Can you agree to disagree so we all stop getting notifications? Thanks, have a lovely Wednesday :-)
• 1 0
@mountainsofsussex: We're Americans. We are trained to argue about everything now

Consider it done. And just an fyi, there is an option to unfollow a conversation, at least on desktop version. Hadn't considered the notifications going out, apologies.
• 1 1
@mikealive: You can comment about anything you want. just don't freak out when people wonder why you're commenting on topics not covered in the article.
• 71 4
All the maths,science an lab experiments will never change the fact that a lighter bike feels better One thing's for sure though, loosing the beer belly is healthier an cheaper! And WILL make you faster
• 25 7
Totally agree. All this theory is kinda blown out the water when we consider that those who’ve followed this theory through by adding extra unsprung weight have always gone back to the ‘normal’ bike setup. I think we should not be looking at mountain bikes in the same way as a machine like a motorcycle and stop trying to apply similar theories. We are dynamic, the best rider is the one most at-one with their bike.
“But there are some exceptions where this logic doesn't apply. In particular, when bunnyhopping, pumping, carrying your bike, or technical climbs involving manoeuvring the bike up and over obstacles”
- that is mountain biking. So…I guess the logic doesn’t apply.
Solid theory, a great piece from Mr Stott but I just don’t believe it’s relevant to real world mountain biking.
• 20 0
Id agree. Its like saying that picking up a can of beans is easy as its not very heavy. OK fine, now hold that can of beans with an outstretched arm for a while. See how heavy it feels now. Yes bike weight itself won't have a specific advantage or disadvantage on its own vs overall system weight; thats basic maths we can all do, but add in a lever or two (arms and legs for example) and its a whole different ball game.
• 2 0
@benpinnick: YEP! after a 25mile trail ride I'm cursing my bike that now feels 10KG heavier than when I set off
• 8 12
Disagree i prefer a bike that is not too light. sub 30 lb is too light and feels unstable to me.
• 3 0
But it’s easier and more clickable to claim system weight has a linear correlation with mountain biking performance. If only “15% faster” was as easy for manufacturers to achieve as dropping 3 lbs
• 12 0
I tend to agree. 1% weight difference in paper might not be much, but flickability, liveliness, and quick acceleration are all very noticeable within a couple pounds of weight loss, and all those attributes equate to more fun.
• 4 1
It's completely relevant, BUT weight is just one factor amongst many. Like every other thing in this sport- what will make the most difference to todays ride: 1 degree steeper seat angle, 1 lb less weight, .15mm thicker rotors with 9% more braking force, a 38mm fork that's 17% stiffer than a 36, eating oatmeal instead of an omelet for breakfast? Who knows. Except at the outer edges of the sport, none of those things individually except breakfast probably matters much. Put them all together and it's probably pretty dang noticable- but several work against each other /shrug.

I'd alway prefer a lighter bike to a heavier one, but if they are within a reasonable gap then it's just one of many checkboxes when it's new bike buying time.
• 17 0
Completely agree. We can talk about 1% or 2% all day, but math doesn’t explain why my carbon framed enduro bike was way more fun to ride than the aluminum framed version I replace it with when the carbon one broke. There is 2lbs difference between the bikes with the all the parts swapped over, but a world of difference on the trail. hops, pops, bonks and spins were fun and effortless on the carbon frame, and very muted and exhausting on the aluminum frame. Where does the 1% fit into that? I used to think weight didn’t matter, until I owned a light bike.
• 4 0
BEER! When I added 5 pounds between gravel races that were two weeks apart, I definitely felt it on the climbs!
• 4 0
@tfriesenftr: exactly my thinking. Riding experience trumps the theory imo.
• 2 4
"a lighter bike feels better"

Very subjective. I'm a heavy dude that like to smash trails, to me, too light of a bike feels fragile and too easy to get tossed off line out from under me. I can rely on a certain amount of momentum from the bike allowing easier inference on where it's going to go if/when traction changes suddenly.
• 1 3
@ProperPushIrons: The relevance of this story isn't whether lighter or heavier is better for everything (since that's very very subjective). It's an objective look on weight vs climbing with a bit of objective generalizing about descending.
• 2 4
@blackthorne: Quick acceleration doesn't go with the others. You can't accelerate just the bike, you have to accelerate the rider as well. So you're back to Seb's point that a couple pounds is only ~1% of the total weight, and that's what will effect the acceleration.
• 3 3
@tfriesenftr: I think you're missing the point of what carbon fiber construction is really good at. Not only can they drop weight, but they can use the remaining weight to tune the frame's flex and rigidity to better match the suspension forces, the trail forces, the rider forces, just about everything. A carbon frame isn't just a clone of an alloy frame in a different material, the different construction methods both allow and necessitate changes in feel.
• 6 0
@justinfoil: oh believe me the difference between a heavy cheap wheel and a lightweight carbon one with light tires is night and day. Much more pronounced in road biking also. Lower rotating mass means less effort to get the bike up to speed. Rotating mass has direct effect on acceleration and that’s something that can be objectively measured and felt.
• 45 1
I had a chance to ride a really light bike and it was eye opening. Effortless acceleration, climbing was actually fun, so nim and l felt like attacking the trail. It was impossible for me not too! There are lots of variables but once you ride a light bike everything seems heavy.
• 21 1
I’m on team weight-weenie, and I fully agree.

Obviously, balance is everything. And I wouldn’t take issue with many of the points in this article. Losing weight if you’ve got too much of it is a much more cost-effective way to increase performance. There are plenty of times when marginal weight improvements in your bike are unjustifiable from a cost standpoint.

Take a look at something like the Transition Spur. Are you getting much “value” upgrading from the 25.2lb X01 build to the 24.7lb XX1 build for an extra \$2,700? Not really.

Would any of us notice a significant difference between the 29.4lb Deore build and the 25.2lb X01 build? Absolutely. Worth spending an extra \$2k on? I’d say so. If you can swing it.

Which isn’t to say you couldn’t have a blast on a 29lb “Downcountry” bike, or a 35lb trail bike or a 40lb enduro bike. But if you’re going to be pedaling it up, I’ll bet we’d all appreciate taking a few lbs off those weights, and in many cases, find some value in investing in a lighter build, to a point.
• 9 8
@seb-story real world results couldn’t be further from your claim, in my experience. I have repeated timed circuits with power meters on both a 26lb 120mm and 32lb enduro bike. With the power meters, HR and RPE, I can directly compare efforts.
Bottom line is climbs can be up to 10% different in times, but most descents are within 1-2% (up to limits for the short travel bike).
Wheel weight directly affects downhill performance, the lightweight wheels of the 26lb bike noticeably slow down through chunder and don’t track as well at speed.

IMO if you could have a 25lb complete trail bike, with the wheel weight of a typical enduro bike, then you could have some magic.
• 8 0
It's all about that "nimbility"! Where I live the trails have short climbs along with short downs. We pedal ALL the time here. I took 1.5lbs off the bike by changing wheelset and it was like a different bike entirely. Those sharp turns into a steep climb were SO much more fun. Doubles became effortless right then.
• 5 0
@g123: "(up to limits for the short travel bike)." - that is a HUGE qualifier that kind of throws everything else out.
• 6 0
@g123: you have to add the weight difference to the same bike in order to control for all the other variables (pedal bob, likely different tires, etc). He mentions this in the article
• 1 3
@g123: So what you're saying is that if I lose ten pounds of body fat, I will be 10% faster?

Wow, that's some amazing science you got there bro
• 2 2
@Thirty3 "Effortless acceleration" is going to be from something besides just weight. You have to accelerate yourself as well, so unless you're dropping like 20 pounds from the bike, you're only talking a couple percent total weight change, and that's what it takes to make acceleration "effortless", well I guess you just have a different scale.
• 3 5
@flaflow: "Doubles became effortless right then." I would re-evaluate your jumping technique. You have to move the bike _and_ yourself to make a jump, and dropping just ~1% of that weight should not cause doubles to become "effortless".
• 4 0
@justinfoil:

Bike-body separation —- on an tech trail, the bike for sure moves differently (more) than I do, thanks to pumping, hopping, lunges, etc. Thats the “million little accelerations” many commenters have touched on.
• 1 0
@AckshunW: I have to remind myself how the trails we ride, the way we ride, varies so much it is no surprise we have different stories.
• 1 0
@ICKYBOD: agreed it is a qualifier, but meant to mean anything short of full-on dh terrain. There is of course an overlapping spectrum of terrain where a short, mid and long travel bike works best, skills being equal. My observation was made to address the gist of what Seb was getting at, keeping in mind that ride performance is about the up as well as the down.
• 2 0
@HtownGiant: absolutely true. But consider most people buy a bike for the “style” of riding that they identify with the most (xc, trail, enduro etc). I’d argue that maybe trying a fundamentally different bike might change some minds. The latest gen short/mid travel rigs have progressive geo and light weight - overall super capable on most trail.
• 5 1
@nurseben: I think you already have your mind made up… but that’s not how it works. The ability to continuously accelerate over rough terrain and keep momentum is what seems to make the big difference in climbing pace. The light bike just does that thing better.
It’s not science. But it is repeatable and based on some measurable things, which is more than nothing. And yep, for the same power output the climbs can be that different between the 2 bikes, the numbers don’t lie.
• 3 0
@justinfoil: I've ridden the full gamut of wheel/tire assemblies; from ultra heavy to carbon ultra light. The ultra light setup really does feel effortless. My rotational is what I would consider in the middle/light area. However when I have hopped on friends' bikes that have heavy rotational it was massively apparent how heavy they were and how much more effort it took to get them going. I now have a dedicated heavy af wheel/tire assembly for weight lifting/training.
• 45 8
I worked in North Vancouver years back and told a few customers to take a dump before they went for a ride, kept a straight face too! Easy 500g saving for \$0. Sometimes Australian humour doesn't translate to a north American market but that's all part of the fun!
• 20 1
You can do all the math you want. A light bike is a fun bike. For my type of riding and local trails, I'm willing to give up a little on stability and have a bike that's easier to throw around ,climb,accelarate and brake,and even carry on my back if I decide to climb some hiking trail.
• 3 0
Yeah Light bikes rule!!! I just hate that I can't see my 28lb beauty when I'm riding down the trail because of my giant gut and fat ass
• 21 3
The actual impact of suspension bob is also an interesting topic. Dylan Johnson suggests that there may be practically no benefit to locking out suspension.
It would be great if Seb looked into that.
• 4 7
@Konyp agreed. assuming a perfect pedal stroke, bob isn't induced by the power applied by our legs. if their is no wheel spin and the hub is fully engaged, the same pedal cadence will result in the same forward movement regardless of suspension action.
• 5 3
Agreed, I think the effect of pedal bob is mostly psychological. An obsession with it 15 years ago gave us spv, motion control, and propedal, which I thought degraded suspension performance
• 5 1
Watched this video awhile back and its been living rent free in my head ever since. Pinkbike even somehwhat confirmed this as well when they did the efficiency test with the hardtails and they were on par with the other full suspension bikes.
• 10 3
When you bob, you're putting energy into the bike to push it down. The spring gives it to the damper on the way back up, which turns it into heat. That's your energy loss, plus the exertion of having to control your body. Go try yourself-- put the bike in an easy gear and pedal a little too fast. You'll bob all over the place and go almost nowhere, but feel just as tired as if you were covering real ground.
• 6 4
@tdcworm: Um, might wanna go back to school on that one. Energy from the pedal stroke *is* being lost through suspension movement instead of forward propulsion, which is what you want. However it’s not that simple either, if the rear was completely locked out you’d lose energy through tire deflection and less grip.
• 1 1
@blackthorne: yeah, damn damping!
• 1 5
@alexdi: well according to the studies in a real world scenario there is no difference.

Remember back to physics when you drag a cylinder across a surface: it takes the same energy to pull it from the center of mass than it does it pull it with a string wrapped around it and thus making it rotate (seemingly more motion).

also the bob is not a result of the pedaling, its just shifting your weight, and compounded that the energy into the suspension is given right back (minus friction yes but not very much),

i find it counterintuitive as well but idk I leave it open
• 5 2
@alexdi: @blackthorne Maybe you guys should watch the video before patting yourselves on the back? He cites scientific studies to back up his claims as well as a personal test. The bike used in the studies is from the early 2000's so suspension tech wasn't the most refined either. Also he, and GCN, both did separate videos about clips vs. flats that are quite interesting. I remember an article on here a while back claiming some 15%-30% more efficient for clips when in reality there is none as far as pedaling goes.

Dylan Johnson's Clips vs. Flats Video: www.youtube.com/watch?v=KUEaN9FKGLE&t=1s
GCN's Clips vs. Flats Video: www.youtube.com/watch?v=CNedIJBZpgM
• 1 2
@rad8: Yes, we got those inventions 15 years ago, but the obsession is far from over. Look at how popular it has become to talk about anti-squat, and the almost ubiquitous mention of not needing the climb switch on any bike with prior mentioned high anti-squat.
• 4 5
@blackthorne: Um, might wanna go back and check your reading comprehension. I specifically stated the assumption "perfect pedal stroke." put your bike on the stand and spin the cranks and report back to me the affect it has on the suspension. i'll give you a dollar if your suspension bobs in that state. clean up your pedal stroke, and you will clean up your bob.
• 2 2
@mariomtblt: If your suspension is moving on a flat surface, that's energy loss.
And in this case, you are the only energy source, so it's your energy wasted.
There would be no loss from suspension if this was an electric moped with constant force applied, since the only loss would be in the initial compression of the shock.
However, on a bicycle, you will never achieve constant force on the chain, force will be roughly applied in a sine wave form, with some pretty large differences in force during the stroke.
This variable force will act on the suspension through the chain in varying degrees based on the instant centre of the suspension design, causing some energy loss.
• 2 1
@tdcworm: That's a lot of assumptions.
• 2 2
@preston67: no its not a lot of assumptions. its exactly one assumption. and the proof is born out by in the saddle vs out of the saddle pedaling. you will always experience more bob out of the saddle than in saddle. as a matter of fact, you can induce bob on a full rigid bike....it's not the kinematics fault.
• 2 2
@tdcworm: To really do it right, you need to remove the shock (or get its resistance to zero) and also get it to sit near sag. Pretty much every bike will impart a force on the suspension through the chain as the chain tries to pull the rear axle forward. This is part of most designs anti-squat (there is also anti-squat due to the wheel pushing the rear axle forward. dw-link utilizes this to great effect, but that's not an effect when in a stand). You will find each pedal stroke does try to extend the suspension (or compress on the rare bike with negative anti-squat around sag), and that's part of bob as well.

Really high anti-squat bikes, contrary to popular belief, can have a tendency to bob more since no one pedals perfect circles. I pedal reasonably decent circles (I can pedal one-footed on flat pedals), but I still like bikes with middling (75%?) anti-squat for both that reason, and because I love traction more than I care about raw pedaling efficiency: a tire slip when climbing over a root is usually way worse that whatever minimal losses come from active suspension.
• 2 2
@justinfoil: all true, but the fly in the ointment, is that, regardless of antisquat, uniform chain tension will result in the sinusoidal amplitude of pedal bob returning to zero quickly. while unrealistic, its why i qualified my position, by starting with base assumption of perfect pedal strokes. none of us has a perfect pedal stroke, especially on a trail. but it does highlight the point that we can point the finger at the bike all we want, but it doesn't assume any behavior without rider input, which, at best, is highly variable. at the end of the day, it's a poor carpenter who blames his tools...
• 1 1
@tdcworm: why would you ever base a position on an unrealistic assumption? That's silly. Also, a good carpenter doesn't settle for poor tools, they would make them good tools. Dull saw or chisel? Sharpen it! Square not square? Adjust it or use something else. Can't really change some things on a bad bike. If it's sold on the premise of not bobbing because it's got high anti-squat, there isn't much the rider can do when it's bobbing under the real world situation of non-uniform chain tension.
• 1 3
@justinfoil: why use an unrealistic assumption? because PEDAL bob is the result of imperfect PEDAL stroke 100% of the time. antisquat and dampers can fight it, but as the rider's pedal stroke pulses, so will the bob of the suspension, in unison. and even though you may not feel it, it is still there. stop applying pressure for a split second, and the bob disappears. similarly, your fork bobs and your tires bob with every imperfect pedal stroke...and neither of those have any antisquat. stand up and pedal out of the saddle and all of that is exacerbated because the saddle is no longer controlling your hip motion.

by the way, a dull saw or a dull chisel is not a poor tool. its a worn out tool that is cannot be used as intended. that would be akin to riding a bald DHR II in the rear and blaming lack of control on the DHR II. a DHR II is widely accepted as one of the best tools. run it until it is bald and it's lack of performance has zero to do with it's design. hardly analogous to a carpenter whom can't build a plumb door jamb because he cannot use a bubble level or plumb bob, then blames it on the otherwise performing bubble level or plumb bob.

at the end of the day, pedal stroke efficiency is not binary, and each of us, pros included, can work to improve our pedal strokes in pursuit of the perfect motion....just like every carpenter can hone their skills in pursuit of the perfect cut or angle. an easier way to say it: improve your pedal stroke, and you improve EVERY bike, even the best ones...
• 1 2
@justinfoil: every vehicle has anti squat, but the only vehicle with suspension bob is a suspension mountain bike. its also the only machine that delivers its power in pulses.
• 2 1
@tdcworm: a lot of things deliver power “in pulses” like for example a steam engine train
• 2 2
@mariomtblt: touche...good call out.
technically any piston driven system pulses...turbines and electrical motors do not. but all of those piston driven systems operate at much higher RPMs [than the cadence of our legs] that increase frequency, smoothing out the response.
• 2 1
@tdcworm: I think it's a flywheel that smoothes out an engine. Not an increase in rpm or frequency.
• 1 1
@littleskull99: either works. increasing speed (rpm) or increasing the mass (flywheel) both increase angular momentum, and that's the smoothing factor.
• 2 1
@justinfoil: The centripetal force generated by the imbalance multiplies exponentially with the speed of rotation (doubling the speed quadruples the force), creating a shake or vibration.
• 1 1
@justinfoil: making my legs spin faster does not get rid of suspension bob.
• 2 1
@tdcworm: "stop applying pressure for a split second, and the bob disappears"

What? Stop pedaling? If you're not pedaling of course there is no bob. Is that supposed to be some kind of revelation?
• 1 2
@justinfoil:
if you'd take a break from your obsession with being right for just a second, you might be able to acknowledge that PEDAL bob has many variables, one of which is PEDAL stroke. you admitted you didn't want to consider it, because achieving a perfect pedal stroke is not possible. enjoy being a carpenter whom has no interest in pursuing perfection of your craft. #revelation
• 3 1
@tdcworm: you keep mentioning this perfect pedal stroke as if it were somehow an unknown quantity. It’s like saying ‘well if there no gravity we could jump forever’. And?
• 16 2
There is another factor worth mentioning for those of us who fly with our bikes. Most airlines in the US have a 50 lbs weight limit for bikes to fly as standard luggage. Over that and you have to pay an oversized luggage fee. Right now my bike plus Dakine shipping bag are about 7 lbs over the limit, so I have to take off parts and pack them in my other checked bag. Currently I take off all the easy stuff and now have to take off the cassette too. This is adds a bit of time and hassle on both ends. Paying for lighter parts to reduce how much I have to strip off the bike to stay under the weight limit is my key driver for weight reduction.
• 32 2
Not criticizing, but as far as reasons to drop weight go, that's a new one on me. As an absolute featherweight, it also makes me wonder if flight prices should reflect a person's BMI.
• 2 0
@BenPea: What is interesting is that it provides a very clear relationship between bike weight and money/time saved. Performance, of a different type, and one predicated upon a set of rules handed down by the airlines.
• 11 1
It's a very first world problem but it's a good point.
• 1 0
@phillyforester: Absolutely. There's a certain number of flights/year at which this becomes an actual issue.
• 5 1
@BenPea: I'd love to see this.

Each ticket gives you x amount of KG's.
This includes, checked bags, carry ons and your fat ass.
• 7 1
@Allen82: it's a dangerous road to go down though, because who's to say such discrimination is fair. If you're 2m tall, you're never going to weigh 60kg, unless you're sick. Plus genetics, plus other disorders, plus mental health, etc...
• 1 0
My motivation too.
International is no problem but AU internal airlines are thieves.
If I can get my 5” trail bike in domestic flight luggage without paying the \$70 excess I can ride most stuff and put the savings to better use at the pub post ride.
• 1 5
iiman FL (Oct 20, 2021 at 3:29) (Below Threshold)
bags are for roadies, every time I see a MTBer with an Evoc/whatever bag I assume money is no object to them.
£300 bag, plus bike fee, plus overgeight fee straight away.
A box is 100% the way to go, last saturday I carried my 15.5kg porker, shoes, half lid and pads, all weighted 23kg

BTW, for the euro crowd, Ryanair sucks and bike fee is £60/flight, but their allow up to 30kg
• 3 2
@BenPea: The airline's costs are almost directly proportional to the weight moved, so is it "fair" that they should make less profit on bigger people? I'm all for charging by weight including the passenger, people would make every effort to minimise the weight they took and this would benefit the environment... But obviously, if someone is bigger, so paying more, then they should get more space too. If someone 2m tall was paying 20% more than someone 1.86m tall (cube rule) then they should also get 20% more legroom and more elbow room. For a lot of tall people this would be a bargain compared to "upgrading" to premium.
• 1 0
I think you'd save money if you went with a lighter bag rather than lighter components.
• 1 0
@iiman: I disagree. Over the summer I flew about 1500 miles to go ride and I checked cost on a cardboard box and just shipping my bike compared to just bringing it with me on the flight. To fly with me it was cheaper so yeah bag is expensive but over time it’ll be less hopefully.
• 4 0
@iiman: try carrying your stupid box over a longer distance or up stairs, or along a crowded walkway in the rain. I did it, in Paris, it sucks. It sucks hard.
• 5 1
@BenPea: I often wonder why I have to pay the same amount of money as someone who weighs 50kg more than I do. I take up less space, it requires less fuel to move me across the continent, hell, even my clothing weighs less, etc.
• 8 1
@BenPea: Can imagine the titanic PR shitstorm that would be created when airlines start weighing people?
• 12 1
@BenPea: I don't think fat people should have human rights.
• 4 0
@G-Sport: It’s fair in theory. Will never fly in the real world.
• 2 0
@LeDuke: you take up less space? If you aren’t sharing a seat with someone then no, you don’t take up less space.
• 6 0
@Losvar: In a way, those who are overweight are more human.
Loving the Norwegian sense of humour (?).
• 7 0
@bogey: The fat dudes overflowing into my seat are most certainly taking up more space than me.
• 2 1
@G-Sport: I agree with you, but then again, someone will be entitled to use the bigger space because they paid more. Not a problem, untill the taller will have to pay more, and use the small space. And then a lot more of problems will rise. When talking people, we should be talking equality, not some other way of discrimination. We already have enough of that around.
• 4 1
@Notmeatall: please help me get these worms back in the can, I've accidentally triggered a fattist revolt.
• 2 0
Last US internal bike flight I took I was allowed 70lbs. This allowed me to pack tools and cloths in the box.
• 2 2
@BenPea: Maybe not BMI cuz that's not really reflective of anything other than health, but it would make sense to charge by weight... and I'm 200#
• 3 1
@nurseben: Let me ask you guys this — what is even an extra 100kg on a person compared to the total weight of the plane and everything in it, and all the power it takes to fly? I’m not talking about a Cessna or one of those little puddle jumpers where they are always asking people to sit in the back to balance the weight. Big planes, like 747s. How much different is it for the plane if a person is 75kg like me, or 175? My guess is not much in the whole system.
• 2 2
@nurseben: BMI is poorly related to health. Generally fitter people have somewhat high BMIs due to higher muscle mass.
• 1 1
@Muckal: I live in London, and none of that is an issue since I discovered the box goes resting comfortably on top of any 4 wheeled cabin size case.
• 2 1
@bogey: BMI is reflective of health in the same way weight on a bike doesn't matter much. They're both BS statements a lot of the time.
• 1 0
@iiman: I've travelled with cardboard boxes, they absolutely suck. Less protection, and if you travel with friends, 3 or 4 cardboard boxes take up an insane amount of room in a hotel or condo. Evoc bags give better protection, roll nicely and pack down fairly small when you arrive. You can find them on sale from time to time around \$400 Cdn (£230) and other brands even cheaper. Never going back to a cardboard box.
• 4 0
@BenPea: I have no problem discriminating against fat people...
• 1 0
@iiman: good point. I actually thought about strapping an old skateboard to the box, but didn't. That was one poor descision.
• 2 0
@BenPea: Well, we have better things to battle, like drivers that think cyclists are not fully humans.

www.cyclingweekly.com/news/racing/half-car-drivers-think-cyclists-not-fully-human-according-new-study-411816
• 1 0
@Notmeatall: well that's bloody marvellous isn't it... And if the drivers in question happen to be fat, that raises more questions. At this rate, there won't be any full humans left.
• 1 0
@Muckal: I used to think boxes suck before discovering the trolley trick, I even though of building a small corner piece with skateboard wheels for the box, but now I just put it on top of the trolley and done, just need to keep it balanced. And really, if there's no lift carry a bag upstairs is not any easier...
• 1 0
@bishopsmike: I'd argue they're more protective. Have you checked any bike box lately? is pretty damn strong cardboard. Bags don't have hard sides. If anything, I'd say their advantage is luggage handlers are less likely to lay them flat with stuff on top, but precisely cause they're more flimsy
• 1 0
@BenPea: You do have a point there, they are indeed more human.
Maybe they should have extended rights then?
• 2 0
@Losvar: Or maybe the food industry and complicit governments need to sort their shit out and stop treating people like cattle that needs fattening up for slaughter before being sold by the kilo. And that's just one aspect.
• 5 0
@BenPea: People and their choices drive the market. When people choose to buy and eat healthier foods, the market will change. There's a good financial reason Amazon bought Whole Foods, they see that healthier food choices are starting to become more mainstream.
Blaming the food industry for trying to do what it's designed to do (making money from selling food) by the typical "make it cheap, sell it fast" model makes it easier to live with our shitty food choices. Truth is, it's on us to eat healthy, there are plenty of options in most places.
• 6 0
@Abacall: junk food and sugar are addictive and are responsible for a hell of a lot of disease and death that people don't choose. It's almost hypocritical that there's still a war on drugs when obesity and diabetes are arguably worse for society, despite being caused by industries that are not only legal, but which fund political parties. How many people comfort eat due to poor mental health or just because they crave it? Do they crave salad? No it's chocolate and kfc. Choice is such a nebulous word. Nobody chooses to eat themselves to death, but marketing preys on their weakness. We all have weaknesses.
• 4 2
@BenPea:

Anyone who is obese has no one to blame but themselves. Sorry.

Yes. Sometimes people's lives are hard and things get them down so they might eat.
But it's their choice.
They could do something else to make themselves feel better.

I don't know about everyone else but I feel best after I've exercised.
• 1 0
@TheR: For 200 people on a plane, that's 22 tons, which is quite a bit.
• 1 1
@usmma2013: Yes, but the plane is designed to the carry weight of 200 people. Does it really matter in the scale of the whole system if some people weigh even 100kg more than average? Or is it like a 100g on a bike — insignificant? And 100kg more is A LOT. Most people won’t weight that much.
• 1 0
@TheR: I'm by no means any sort of expert here, but extra people weight likely takes up the allowance for cargo weight and this can be an important part of the airline business. So yes, it matters.
• 1 1
@bogey: And I realize there’s a capacity, and it’s probably pretty high. But I’m guessing there’s a range based on a target passenger weight. Someone threw out 22 tons — so let’s say the limit is between 20-30 tons. If a few passengers were 100 pounds under average (kids), and a few 100 pounds over average, at what point is it making a different within the max capacity range? I suppose an overweight passenger or two might make a difference on some occasion, but rarely.
• 1 1
@bogey: people aren't weighed when they buy a ticket so there will be a fixed cargo payload.
They do distribute passengers in a half empty plane to make the thing more stable though.
• 1 0
@BenPea: you don’t think airplanes have sensors for this?
• 1 0
@TheR: Sadly, you are not the only passenger in the aircraft.
• 1 1
@bogey: for what?
• 1 0
@BenPea: food and drug industry is tightly bonded. They will change only because of regulation, not because they can improve.
• 1 0
@MaplePanda: yes, exactly. There are 200 passengers in a range of weights. That’s why a single passenger doesn’t matter that much. All 200 passengers weighing 150kg, maybe. 3-5? Not so much.
• 1 0
@TheR: I have to wonder what the average human cargo weight of a flight departing from Denver vs Atlanta is.
• 1 0
@BenPea: Agree with that 100%. Ultimately, it's a matter of education, moderation, and wanting to make a lifestyle change. I think ultimately what we do with our lives (and our diet) is still our choice, albeit not an easy one to make with the availability of unhealthy foods and confusing science around eating.
• 14 0
All my life I thought that a heavier bike would be beneficial because of the factors that you wrote, but recently about a year ago I changed my bike from a full aluminium 2017 Scott Gambler to a YT Capra 2017 full carbon, frame, wheels, bars and cranks. What I noticed is that the bike was noticeable faster when accelerating and felt more agile and easier to turn, almost all of my Strava times got better (the tracks I ride are mostly DH tracks or super rough enduro tracks, without climbs on the middle), But there was a catch, the Capra is much rougher on my body even though it has 180 mm of travel, I have to choose my lines much more carefully or I will have tons of arm pump, and the Gambler was like a magic carpet going through rough terrain. Finally, my Capra weights 14,3 kilos and the Gambler weighted 18,2 kilos
• 8 0
Yeah I experienced the same thing 10 years ago when going from an aluminum Intense 6.6 (31lbs) to a carbon Intense Carbine (27lbs). Instantly, much faster climbing/accelerating, more flickable/agile, but on super tech downhills it was less stable and tougher on the body. Always compromises. On top of that, the instant difference in weight is short lived once your legs adapt. When the honeymoon is over, the lighter bike does feel just as hard to climb with. Goes back to the concept that it never gets easier, you just get faster. Haha.
• 1 0
Dam, the 2020 gambler weights 15,5kg in race spec. Your time improved probably because of better lines if downhill only.
• 12 0
What about the effect of accelerating over and over again?
In classical physics, yes, the system mass is what matters going uphill.
But humans aren't machines, and we are maybe pedaling with a frequency of 1-2Hz up a steep climb. Every pedal stroke cause acceleration & deceleration. How does doing this over and over again play in?
• 2 1
This is it right here. The article was an oversimplification that neglected possibly the most important pieces of the equation. With every pedal stroke and every bit of movement on the bike, we are accelerating it and this plays a big part in how the bike feels and how fast it is. Looking at it as steady state, in lab conditions clearly does not match up to real world experiences.
• 11 0
Apparently the math doesn’t add up to my real-world experience. I have ridden burly rims in my bike, then switch to lighter one, and the difference was extremely noticeable. Mtb is constantly slowing down and accelerating. So take that 1% and x it by the million like changes in speed and you have something noticeable.
• 3 1
Yeah I think the takeaway is to not give to craps about FrameWeight in general (and carbon perhaps??). BUT...I'm with you on the lighter wheel stuff. That is real with a significant feel in both pedaling around and up but also in the fun factor of the downs. I tested this out with my 70lb son on a wheelset of like 1800-1900g and then put on a wheelset that was 1300g. Massive difference that he instantly felt, and loved.
• 12 1
So there is a benefit to me strapping loads of crap to my frame rather than carrying it in a bag. And we should be a dick about it when there's no room for a water bottle on a new bike!
• 4 2
Yeah, I'd say it makes sense to store as much as possible of your kit and water weight on the frame rather than the body, for the rigid-sprung-mass to total-sprung-mass reasoning discussed above. I'd always fit a water bottle if I can and if I have extra water on my back I'd drink that first.
• 4 0
Stored on person on the way up, on the bike on the way down! Options are awesome. You can be that guy who's moving shit from your pack to your frame at the top.
• 6 1
@seb-stott: my experiences trying to ride technical trail or jump a fully-laden bikepacking hardtail, compared to riding technical trail or jumping it without all the bags, begs to differ.

How that weight on the frame is distributed has a huge affect on handling, so it's hard to blanket-condone strapping weight to a bike willy-nilly for downhill handling benefit.

I'd also note that my bikepacking rig handles a lot better if I put as much weight as possible on my back. Getting a comfy hydration backpack for much of my water rather than having it on the bike made it handle a lot better for bikepacking on anything but smooth terrain.

Pumping the bike through terrain, and weighting/unweighting it at appropriate times, hugely affects downhill performance. The heavier the bike, the harder to weight/unweight it at appropriate times to absorb terrain (which is more effective than letting the suspension do it all).
• 1 0
@seb-stott: I think most of the benefit is from lowering the centre of gravity. If you move a kg of drink from up round your ribs in a bag to just above the bb that’s quite a difference
• 2 0
@chrismac70: except that kg of water on your back is suspended doubly (fork/shock and arms/legs). With a small water bottle it's no biggie, but having a few liters of water in a *comfortable* backpack is better than having a couple liters in bottles mounted to the bike for technical terrain, especially if you're on a hardtail.

This is mostly relevant to bikepacking, btw. Small amounts of water/tools/etc. has a far less dramatic difference. Smashing through rock gardens with 3L of water and food on your back is way different than if that 3L of water and food was on the bike, moving up and down more with every bike movement.
• 9 0
Often, the extra cost of going full weight weenie is often similar to a used bike in a different category... i.e. you could make a 160/70mm bike light for \$3-4K with XTR/XX1 cassette/cranks, carbon wheels, lighter seatpost/saddle/bar/stem than spec'd. Or that same money can buy you a more used XC/AM bike (or low-spec new) which is more efficient. Same logic for DH rigs.
• 9 0
I found that lightening my wheelset made a huge difference. The bike weighs what it did before, due to some component changes, but now I can clear tech uphills that I couldn’t quite manage before.

Rotating weight really is a factor
• 2 0
I've found that reducing weight on hoops is good. Also fatter tires makes the ride smooth and faster over rocky and bumpy.
• 12 0
Try bunny hoping an e-bike!
• 42 0
Don't they have a button for that?
• 3 8
lacuna (Oct 20, 2021 at 2:54) (Below Threshold)
Shouldn't be a problem. My Banshee is heavier than just about any e-bike and I could bunnyhop that more than 2 and a half feet. www.youtube.com/watch?v=sW_-vm0EYCk
• 2 0
haha I have, I could probably jump over a pencil ;P. So impressive when Sam Pilgrim or Danny M just make it look like a normal thing (let alone when they do stupid stuff like a 180 from flat with no speed)
• 2 0
@lacuna: Impressive! Thats a beefy bike. What I felt when I played around with it is it's not that you can't get the front wheel up its that it's just a lot less explosive. Which makes sense, go do a jump squat with 60lbs then 30, and that's a lot simpler movement shorter movement requiring less body mechanics and only using the biggest muscles available.
• 3 0
I would love too, but I cant afford one, and I cant bunny hop
• 3 0
I would but then I'd spill the beer and pizza strapped to the back of the bike.
• 1 0
nah
• 8 0
Idk, all I know is when I go from my 30lb tb4 to my 25lb dv9 it’s insanely obvious. The dv9 accelerates soooo fast for a 29er, obviously a big part of that is because it’s a hardtack, but you can feel the weight difference very clearly.
• 7 0
My \$0.02 worth, I traded my old and faithful DH bike for something a little lighter (it's 1936 grams different) because I've found as I get older, the repetitive runs were far less fatiguing with the lighter bike. I'll be doing the same with my trail bike in the not too distant future for the very same reason.
• 8 0
Wouldn't it be totally different if you were calculating everything only with the bike weight and not rider weight+bike. After all we are carrying our weight all the time, doesn't seem to be exactly the same, is it?
• 1 1
For jumping, and pumping, and unweighting, and high-speed traction, and so many other things, yes. But purely for comparing work done to achieve the elevation change of a climb, the total system weight is the primary factor.
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@seb-stott there is a point at which all of the above math tips in the opposite direction. it's when we consider that the motor of a bicycle has a finite fuel tank and a finite duty cycle. reducing weight will drain the fuel tank more slowly and increase the duty cycle of the engine before preventative maintenance is required.
• 8 1
This a rather simplistic application of physics to the weight effects of a bike. For one, on a mountain bike, you are pretty much constantly accelerating, every time you go over roots, rocks, and the varying slope. So that 0.4% difference of rotational energy over an hour and a half (or more) is actually a lot more in total energy expenditure, not just 0.4%. As for climbing, the same thing, it all adds up. Also, the important factor here is Watts, which is energy/per second. Using change in gravitational potential energy is the minimum energy you can expect to use to get you up a climb. But it does not take into account how fast you make it up that climb. For example, one person climbs a 100 m in 2 minutes, and another in 4 minutes. They both have the same change in potential energy, but the faster rider used more energy to get up faster. In the end it is all about saving Watts and that is the way to evaluate the weight differences.

The one thing I can say, it is a lot cheaper to lose body weight than bike weight.
• 7 0
While I am onboard regarding weight and the entire system and what small effect lowering bike weight. The issue I have is that when you mountain bike you constantly encounter obstacles that require you to accelerate/decelerate your bike so that small percentage requires a consistently larger energy output.
• 7 0
Sometimes number crunching doesn't correlate with how things perform on the dirt. I notice a substantial difference in acceleration and climbing with my lighter duty wheelset. Also for endurance riders like myself the lighter build exponentially helps during a 50 mile xc race. It's not the 1% advantage on that first climb. It's the fatigue of riding a heavier setup over 6 hours. The lighter setup is a game changer for that 12th climb or whatever in an endurance xc race. It's way more than 1% by then
• 7 0
Weight matters to me a lot - I spend a lot of time pushing, and a lot of time manhandling the bike. Would you rather manhandle 15 bags of sugar around a forest on a Saturday or 11?
• 6 0
In summary:

Your body's strength to weight ratio is much more important than the weight of your bicycle.

Adding weight to a bike affects a lighter rider more than it does a heavier rider - given the same strength to weight ratio between the two riders.

Heavier riders should have better working suspension due to the sprung/unsprung mass ratio, hence the different riding styles between heavier and lighter riders...

Heavier/more robust components are more required for heavier riders as the forces they are putting on the equipment (think hard cornering on wheels & tires) is greater?
• 6 0
The maths is interesting but it's part of the story. If I get on a bike and it feels heavy then I'm already thinking that I am at a disadvantage and that will show in how I ride. Also, in a group ride a 1% - 2% penalty will either make that rider have to push harder and be tired sooner, or it will open a gap where they are at the back of the pack. The mental impact of a widening gap will often make people ride even slower than the weight penalty would account for. I'm not saying it's a good reason to spaff loads of money on lighter parts, just noting that there is more to the equation than physics.
• 3 0
I agree totally. The mental aspect can gather momentum very quickly too when you start falling off the back, just feeds itself. I only have to hear a tacky tire rasping on the tarmac to think I'm already at a disadvantage, whether it's slowing me down or not. Some people who ride in groups need all the advantage they can get, and unluckily I'm one of them :-(
• 7 1
Good article! I've been arguing for years that weight (and especially rotating weight!) is overrated. And rolling resistance and drive train friction are underrated. Of course it makes a difference. BUT the difference is only small and unless you are racing it probably doesn't matter . @seb-stott , I would argue that the reason why people are so convinced that bike weight matters a lot in climbing is similar to your 'rigid sprung weight' argument. When you accellerate, you feel the bike moving forward until it hits your weight. A lighter bike will do this quicker and so feel like it is much faster.
The big counterargument is that a bike that feels faster and lighter is more fun, even if it hardly gets you up the hill faster.
• 2 1
Thanks! And good point about the bike accelerating before the rider's body starts accelerating. This could create inefficiency because every time the pedal gets to 3 O'clock, the bike accelerates, then the rider accelerates with some lag and relative movement. Similar to pedal bob, this relative movement is not elastic and so robs some energy. In extreme cases, it *might* even be an advantage to have heavier wheels that act as flywheels, smoothing out the peaks and troughs of acceleration, and reducing this energy loss (pedal-bob too). That's just a theory though.
• 2 0
@seb-stott: I have seen one study on the effects of pedal bob on power output and they weren't as strong as you would think. It seems that again, what you feel and what you measure are different. Reducing peaks and throughs in acceleration will certainly lower air resistance (force quadratic in speed), and therefore make you faster. If you are interested pm me, I still have some scripts for Matlab that will calculate all that for you.
But is reducing the roller coaster effect really what we want in mountain biking? For pure racers, yes. But if you're in it for the fun, it's better if it feels fast but is slow, than the other way around.
• 6 0
Dude, this part is like, all of mountainbiking, you can't just skim over it because it doesn't easily map to your models:

"In particular, when bunnyhopping, pumping, carrying your bike, or technical climbs involving manoeuvring the bike up and over obstacles; a kilogram on the bike may count more than a kilogram on the rider here."
• 5 0
All i know for my two-pennyworth,is my 2010 specialized big hit on 26 inch wheels was as heavy as fxxk,but was the most fun bike ive ever ridden/pushed Mind you,i didnt have 3 kids,a massive mortgage and wasnt work8ng 60+ hours a week then !!
• 5 0
There is a hill where I live that I use for training on my road bike. My fastest time there is 5:54. It averages 9 % (no big changes) and is 1.63 km long. According to bikecalculator.com, if my bike was 1 kg lighter (there is plenty of room to make even bigger saving) I my time would be 4 seconds faster. Yeah, it's not much, but if I was racing up this hill it could be the difference between finishing 1. or 2.
• 3 0
Yep, for racing, especially at higher levels) all these small factors matter. If you ride on the weekends with friends and are just out riding around they probably aren't worth pursuing.
• 5 0
It doesn't make sense to try to explain the variation in time between the bikes in the impossible climb by weight or anything else before you actually show that there is variation in the time between the _bikes_ in the impossible climb. This article is like a shock and awe campaign of pseudoscience. It's hard to see that it's clearly in the public interest to ask people to think more quantitatively but then ignore some of the most fundamental principles of science; it sends a mixed message. GIGO
• 6 1
I think there one thing missing in all of this... @seb-stott you touched on it briefly but I think it needs to be explored more carefully... and is possibly the reason people report such big differences in feelings when dropping/adding weight.

You explain most of your conclusions based on a "system weight" and while I think that's relevant for sitting and spinning style climbing and maybe sitting and cruising descending (who does that?)... most of other times we're riding our bikes, our bodies and body weight is actually quite disconnected from the bike and it's weight. A lot of the time spent on our bikes is using our body to manipulate the weight of the bike... and so I think many of the percentages you talk about substantially increase when you take away body weight from the system weight.... and there's where you really feel weight differences.

For example... I've been experimenting with various inserts, tire casings and wheel weights for the past few years (I'm an "ambassador" for a few companies which allows me to easily swap stuff around without too much cost)... I've settled on EXO+ casings, Tannus Tubless inserts and a lighter "all mountain" rim (vs enduro). My wheel system weight is actually quite light while being extremely robust and yet supple. Yes, during sitting and spinning climbing, there is almost zero perceivable difference. I thought I could feel a difference at first but that perceived difference seemed to disappear within a few minutes... it was likely psychological. But where I do notice a big difference is on slow very technical climbing sections where I not only need to very quickly accelerate my bike from a very slow speed, but also "hump" my front wheel (followed by my rear wheel) up and over large technical terrain... similar to Pinkbike's "Impossible climbs". That's where system weight, bike weight, wheel system weight and unsrung/sprung mass ratio all seem to separate and you feel the differences. At the same time, I think those percentages multiple exponentially when you also factor "tired-ness" or "fitness" into that same scenario I just described. For a given "impossible climb"... a lighter frame and wheel set is definitely more noticeable once I'm reaching the ending of that climb and I'm breathing through my eyeballs... a 1% difference feels like 50%.

I'd also argue that there are large portions of descending where I smashing through a fast technical descent where I'm pulling and pushing my bike up around and through sections.. sections where the bike is being forced back up into me and I have to control that, sections where you've got to use a lot of body-bike separation to gain grip or control the bike... fast technical corners... slow technical corners, drops, jumps, etc, etc. I'd argue these are other areas where the body weight, bike weight and wheel and unsprung/sprung ratios start to separate themselves from a total "system weight" and various weight differences can be felt more and less in various scenarios.

I don't think comparing the system weight of a bike can be compared to motorsport where the rider/driver is much more a passenger controlling a very heavy machine through much more disconnected means (motocross probably has some crossover there), vs a bike rider who controls a very light (comparatively) bike through very direct means partly with their own weight against the bike's weight.

End of the day... I believe it's much, much more complicated and there are many instances when riding a bike where you can easily feel much more that a 1% difference in various weights. At the same time... I don't think you need to be super careful or spent crazy amounts of money to save weight.. but you do need to carefully consider where you're putting that weight and what ultimately kind of riding you do and what you need out of your total system.

This is coming from someone riding an aggressive 36.5 lb long travel enduro bike.
• 10 2
Bigger wheels are a lot heavier, so go smaller wheel size to save weight?
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• 2 1
@TheR: Yes, he said diameter alone does not effect rotational kinetic energy, only weight has an effect. And that larger diameters are heavier. So, smaller wheels to save weight is a perfectly valid reasoning.
• 4 3
@justinfoil: Yes, but only by 100 grams or so, which he concludes is a negligible amount of around 1 percent.
• 2 0
@justinfoil: Please read my comment down there. His math is wrong. Rotational energy changes a lot with the diameter.
• 4 0
This is worth a watch, only tyres changed, but does show a difference, although the difference is quite small, the riders normal bias would be towards the enduro tyre, so the XC tyre did amazingly well on the descent (not unsurprising from my experience)!

GMBN on the case a year ago, just changing tyres.

• 1 0
• 2 0
I'll just leave this here. Some good evidence that rolling resistance matters more than system weight.
• 1 0
@tetonsorbuttes: I've seen that video before and it was enlightening for purely pedaling performance how much rolling resistance and aerodynamics matter (i.e. bike packing or road cycling), but he clearly states in the "Five situations when weight actually matter" section that #2 "To improve bike handling and feel". Which is reiterating what Seb said at the end of this article "In particular, when bunnyhopping, pumping, carrying your bike, or technical climbs involving maneuvering the bike up and over obstacles".
• 8 0
Just ride ur fuking bike!!
• 5 1
The calculation for rotational kinetic inertia is totally off since you do not accelerate the bicycle by itself.

There usually is a rider in the rider-bicycle system, and it is much more fruitful to look at the total moment of inertia of the rider-bicycle-system. The difference with +1-2kg of mass, and +2» wheelsize becomes negligible to the total moment of inertia of the system, your monthly weight fluctuations during the darl hours of Netflix-season are probably more significant.
It is simply a matter of «feel» to the bicycle
• 5 1
Since weight seems to be a never-ending debate and bike reviewers continuously seem to contradict one another regarding its importance it would be nice if Pinkbike did an extensive efficiency test focusing on this topic alone.

So maybe several bike models with similar components and control tires. But have both the carbon and alloy version of the bike. Or at least add 1 or 2 kg to carbon bikes to emulate the alloy. Having several models with different suspension designs would be interesting too.

And while your at it, run the same bikes with both alloy and carbon wheels or add heavy inserts to look at rotating mass.

And finally, don't do just a 3 min climb up a dirt road. Try several roads with different gradients and/or at least make the climbs closer to 30 min long. This may help explain the benefits of weight difference in qualitative terms as well as quantitative. The sluggish 'feeling' of a bike may also be a factor to consider even if the time differences aren't drastic.

I know there have been other attempts to do this but none have been done properly or have been extensive enough to be conclusive.
• 1 0
Upvote this
• 4 0
The maths is interesting, but it's only part of the story. All the theories and measurements get completely blown out of the water by the amount of people in here saying that they think that light bikes ride better and are more fun than heavy bikes.
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• 4 1
I made the swap to Steel Enduro & 'Downcountry' FS bikes (Cotics) ovet the past few years after riding a lot of carbon from the likes of Santa Cruz, Evil & Aluminium from Geometron. The Steel bikes aren't as Zingy but they have a much nicer riding characteristic, they are very stable descendinders & feel planted. I've experimented with wheelsets & tyre combos & found that this area makes a massive amount of difference to how the bike behaves, I now swap between a light wheelset & a burly wheelset depending on what I'm riding. On my Downcountry bike (Cotic Flaremax) there aren't any negatives it's a very competent bike, climbs well with great traction on techy stuff & descends so well that it gets me into trouble!! i'm 91Kg & 6'2" so I guess a bit of extra weight is negligeable & my levers are long enough to muscle the bike around
• 6 0
So, what you're saying is that, a steady diet of fried food will make my bike ride lighter?

Nice!
• 1 0
lol
• 3 0
I don't care. If having a lighter weight saves me 20 seconds, which might not seem like much but to me 20 seconds is a loooong time on a tough lung busting, leg burning climb. The sooner I can reach the top the sooner I can start to breathe normally and my heart doesn't feel like it's going to explode. Just 10 seconds quicker is nice on those long steep climbs. So I do keep the weight in check.
• 4 0
Those 20 seconds in an XC race could be a difference between 1st and 5th.
• 1 0
you could just go a further 20s slower and not feel as bad lol,
• 1 0
@mariomtblt: Some climbs are so steep and long that even when you're not pedaling hard/fast and in the easiest gear available you're still dying physically. I'm no pro athlete so it's either I stop pedaling or hike a bike.
• 3 0
Of course weight matters which is why in every sport they do everything they can to get it as light as possible. This extends to the point where rules are introduced to stop competitors going below a certain weight. Minnair was looking at the weight saving by using different paint on his worlds bike. If weight didn’t matter then why did he do it? My view is adding weight is a substitute for poor engineering solutions. My current trail bike is 2kg heavier than the one I had 5 years ago. That was strong enough and I’m riding the same trails
• 4 0
Forget about "system weight". A lot of mountain biking is moving the bike around under you. Going from a 35 to a 30 lb bike something you can definitely feel, and the good feelings are what we're going for, correct?
• 3 0
Seb, The first paragraph that summarizes climbing weight vs power is good. It is missing a critical factor though, because it is only true if you are riding your bike up a smooth asphalt climb. We aren't doing that on a mountain bike though. We are maneuvering the bike quite a bit riding up trail. The simple summary disregards all the other inputs needed to get up the trail. We are lifting the weight in addition to propelling it uphill. Also, I am sure most riders have shed weight in many other areas before worrying about thousands of dollars shaving 1,000 grams off their bike. Shoes, helmets, pack, pack contents, tools, body fat, body fat, and body fat etc. Lastly, you don't have to spend an absurd amount of money to shave weight off the bike. Shop smart and look at weights, you can drop weight by spending a little more and making good choices.
• 3 0
I only have to ride my light bike vs. the heavier one to realize that Mr. Stott seriously over simplified this topic.

The simple gravity effect on a pound or two is simple enough and small enough but doesn't even closely to tell the story of actually riding a mountain bike.

Doesn't experience just riding bikes make this obvious?
• 3 0
I have two trial bikes, an Ibis Ripmo and an Ibis Exie. Both bikes have DW suspension design and are the same size.

The Ripmo weighs 31.2lbs (pedals, bottle cage, sealant, ready to ride)
It runs an Assegai up front and a Dissector in the rear.

The Exie weighs 24.7 lbs (pedals, bottle cage, sealant, ready to ride)
I run a burlier tire set up than stock
Dissector up front, Rekon in the rear

There’s a 6.5 lb difference between the bikes, so that should translate to around a 3% differ even in the real world between the two.

I ride the Ripmo on a trail system on a Saturday and then ride the same trail system on the Sunday on the Exie. the idea being I ride the lighter bike when I have been riding for the past 6 days.

Across a 20 km (12.47 miles) ride my average speed on the Exie is 1.8 kph faster (1.11 mph)
- Clearly the Exie is more than 3% faster
- The Assegai tires obviously have more resistance
- The trails clearly don’t NEED the extra capabilities of the Ripmo, and the ones that do, I’m sure the Exie would fair much worse.
- 1.8 KPH never felt so much fun. I love my Ripmo, but on flowing trails with mild rock features, technical climbs and lots of twists and turns, you just cant beat a lighter bike.

Of course there are diminishing returns, and it depends on your disposable income to figure out if its worth it for you.

My Ripmo is a lightest build for a 160/147 bike, but my Zipp 3zeromoto rims are not the lightest because I need the bike to be built strong enough to be reliable for the type of riding it was built to do.

Same with the Exie, I got rid of the lighter tires it came with because they wont work where I ride the bike. I added some weight, but a lot of use ability.
• 4 2
Good article but you’ve neglected to discuss the benefit of the gyroscopic effect of wheel weight. I don’t mind running heavy tyres and rims because the stability at higher speeds is really nice and is due as much to their weight as anything else IMO.
• 2 1
Good point, but most probably the difference in force required to change the wheel rolling plane is also around few %. While it is definitely noticeable (I have switched from 26 to 29) it is something you can get used to easily.
• 4 1
Good point, that's something I left out because gyroscopic precession in bicycles is a really complicated topic.
• 1 0
@seb-stott: I understand that it involves enough physics to take up multiple articles on its own, but I feel that people have enough of an inherent understanding to not be overly confused by it. To me it’s an important behaviour to consider when making whole system decisions. My Mrs has recently added inserts to her trail tyres and carbon wheels as her riding has progressed a lot this (southern) winter. She ended up noticing improved stability above ~15kph. Which is precisely what I would expect from the increased moment of inertia in the system.
• 3 0
Those gyroscopic forces are the reason why I like lighter tyres and wheels (and mullet). It all depends on where and how you ride your bike, but for me as a more playful rider with a clean line choice I prefer light weight and an easy to throw around ride.
• 2 0
I agree that the gyroscopic effect is noticeable and substantial. I have been running Vittoria Martello's in the double ply casing. They have a fast rolling tread and the additional weight is not very noticeable for acceleration, but the increased gyroscopic effect of the heavier tire is definitely noticeable on the downhills compared to the single ply casing.
• 1 0
@seb-stott: I think it gets even more complicated when you also consider the distance between the wheels and the rider - think that the more rotating mass (eg. fat bike, 29+), shorter chainstays (and maybe even a shorter front centre) make more sense
• 1 0
@Ridge-Rider: that’s similar to my approach. I run aluminium rims, no inserts, but fast rolling and wide tyres (at high pressures) with DH casings. Minion SS on the rear (2.3 on 29” trail bike, 2.5 on 27.5” downduro). Dissector or Agressor in 2.4 on the trail bike front. Dissector or DHR in 2.5-6 on the downduro front.
• 2 0
@XIVXV: that’s a fair path to go down. In some ways I agree, it’s part of the reason why I would love to stick with 27.5” on all my bikes. I run light wheels and tyres on my DJ bike, as light as available tyres/rims allow anyway. Ardent race and Ikon, with some rims I can’t remember.
• 1 0
Regardless, there is significant rotating unsprung weight that doesn’t give you any gyroscopic benefit, 12 speed cassettes with big 50t+ granny gears. I’ve switched to the new XT 11s on one bike, I barely use the 50t ring as it stands but just couldn’t bring myself to buy 10s deore linkglide (11-43t). I know the cassette is lighter than the GX eagle I pulled off, but think the lower gears are alloy. If it was more widely available I would try box stuff, but shimano is everywhere, works perfectly, and is cheap. I think a 10s 10-46t cassette would be perfect for me. Using it with a 30t chainring gives top and bottom gears very close to a 32t ring on 11-51 cassette.

The ultimate solution for the non beneficial unsprung weight on a bike would involve the G word....
• 1 0
@seb-stott: Its amazing watching how much of an effect gyroscopic forces have on a wheel. Adding SO much weight to an already large 29er wheel spinning at such fast speeds really requires force to constantly overcome that force or start it.

• 2 0
So much of bike reviews is subjective and ethereal. Weight is objective and easily understood. So, we have adopted it as a quantifiable measure of performance/quality.

People (especially men) like measuring things and comparing the measurements to see which wins. The weight of a bike is one of the very few things we can compare like-for-like.
• 2 0
Rulezman did an amazing video comparing a dual and single crown on an enduro bike last year. Normalizing everything g he could between the two forks and focusing on the difference between the weight and chassis designs. Tons of real world testing with times etc. well
Worth the watch on YouTube as he discussed the affect of the extra weight quite extensively.

Tl/dr it was pretty negligible on a climb of 1,000 meters that took a little over an hour.
• 2 0
I have to admit, maybe weight isn't that important when you are on top of the bike. It depends on the situation, but maybe it's never the most important factor. But there's something else. What about when the bike is on top of you? Like going up unclimbable sections, or even just putting it into your car? It does matter. That's also why ebikes are a different thing altogether. They would break my back!
• 4 0
Ride your bike then borrow an light xc bike. The first thought beside your bike handles good is I wish my bike was a little lighter.
• 2 0
One variable always left out in these sort of studies is the addition energy used to maneuver the bike either up or downhill. Lateral motion during a climb which is literally swinging a weight around, or technical climbing involving throwing the bike forward or up to get over a feature. Similar when descending, it will take more energy to maneuver a heavier bike. I do agree that heavier bikes feel better pointed down though.
• 2 0
There goes big bike again. Trying to sell us that heavy bikes are what we need, that there’s no other way. The resistance knows we deserve a 25lb enduro bike with the spare tube and trail pump, and snacks, and water, and tools included.
• 2 0
I recently got a new bike that is 5lbs lighter than my previous bike. Old bike is Guerilla Gravity Smash and new bike is Guerilla Gravity Trail Pistol, so very similar bikes in suspension kinematics and geometry. Main difference between the bikes is weight and 20mm in suspension travel. It is a very noticeable difference. The lighter bike is much quicker on climbs both tech and smooth and flat sections too. The difference between the 2 bikes is more than I had expected.

A lot of the weight reduction is in the wheels: 1500gram carbon wheels vs 1800 gram alloy wheels + 900gram single ply tires vs 1100+ gram dual ply tires. My guess is the wheels are where most of the change in feeling comes from. I'd like to try the light wheels on the Smash to feel the difference, but unfortunately the bikes use different dish offsets, so swapping is a pain.
• 2 0
1% of total system weight might not be much but the rider produces the power and muscle so its rider weight over the rest of the bike. A 15kg bike compared to 16kg bike when it's the rider that has to wrestle it around a trail it makes a difference. When you hop a root, 1kg difference feels like a lot especially at the end of a big day.

I have a yt capra single speed and no dropper at around 13.5kg, when I jump on my friends whatever enduro bike at 15+kg it feels like a brick and I can't throw it around as easily. Bigger than 1% difference for sure.
• 2 0
Forgot to talk about LIFT. Heavier the bike the harder it is to make lift, meaning front wheel lifts, manual to bunny hop, manuals, and jumping and cornering transition will all suffer the heavier you go. There is for sure a balance of weight to stability ratio depending on what bikes intended for but the geeked out parameters here are typical engineering type jabble that is not relevant to what we really all want our bikes to do better and thats make lift. This is why typical don't know how to shred ebiker doen'st mind the 20 pound weight penalty because they could never create lift on a normal bike so they're not missing anything with their heavy plowsled.
• 2 0
"but a noticeable (10%) increase in brake power"

Not quite sure that's how it works...

A big reason Brosnan might run 220s in the back is for the extra thermal mass and extra surface area to keep them cool, especially since the air flow over the rear brakes isn't as ideal for cooling.
• 2 0
Best article for a while!

After a lot of testing I have Long since started not looking at total weight, just focusing om rotational weight/mass.

That's why spec levels such as "Carbon comp", light frame with heavy wheels, are badly spent money.

That's also why I ride a Knolly with light wheels (and optimized tires, light cassette, cranks)
• 2 0
All this is fine and dandy but what about folding a table 90° on a hip jump?
How many more percent of bicep flex to compensate for 1kg of added weight?
How many sets of how many curls needs to be done to make it the same perceived effort?
How many dollars spent on protein supplements?

• 2 0
This is all so wrong. When I compare bike weights I don‘t look at 1kg - I look at my bikes and compare em to the new ones. One is a SC Bronson with 27.5, Fox 36 Grip2, MM/NN Snakeskin tires ~12.6 kg (including pedals) and a similar LV 301 with even less weight. Both are strong and durable.

Those bikes are mountain bikes - not hardcore bikepark bikes.Superb uphill, downhill and carrying performance, over the top and up to date suspension. Long story short: lightweight but including a ton of fun, easy to throw around in tight corners but 160mm of travel.

Made for the mountains and not necessarily the bike parks, but the Bronson is also fun to ride in a park - maybe it needs a different tire setup.

Would I change one of those bikes with a super heavy 15-16kg (without pedals) truck? No way!!!!
• 2 0
Yeah that is true for most men, it doesn't scale down to women and it doesnt match for kids. And on this point I dont understand why brands build kids bikes with about 15kg. E.g. the new commencal fullys for kids are at about 15kg and for kids at about 25-45kg
• 2 0
This is another industry sponsored bullshit "weight doesn't matter" article. 20 paragraphs devoted to how weight doesn't matter then a small caveat about "system weight is about 100kg". You are telling most women and large percentage of men what they need doesn't matter because of their size. Putting a 60kg women on a 16kg bike is stupid and shows a lack of respect of female riders.
• 5 1
There is a barrier around 16Kg that sucks for pedaling.. specially on the wheels with dh tires... And I am strong pedaler...
• 6 5
The obsession with light bikes is a hangover from when bikes were terrible and lightness was one thing that made them feel better. Weight is hardly important nowdays, bikes ride properly. Make it as heavy as it needs to be to not break and call it good.
• 1 0
I wonder how weight affects jumping? Is a heavy bike going to fly farther ? Which bike would go the furthest distance at relative speeds on the same jump ? Bike A being a 20lb bike w/175lb rider or bike B a 25lb bike w/same rider and circumstances? Im thinking the 25lb -er is going the longer distance but WTH do I know. Any engine-ears? Out there?
• 1 0
I would think at the point of takeoff it's very similar. When I've rode an ebike you get a lot of stability in the air presumably from the weight, but 50lbs going 20mph at a certain angle is probably going the same distance as 30lbs going a certain angle. Obviously it takes different amounts of force to get them both going 20mph though.

Idk that actually knows physics should confirm deny for us ;P.
• 1 1
Yea prob should’ve thought that question through a lil better before pushing the submit button , as sending the 25lb’er @ same speed Would take more energy to start with @michaelandk2:
• 3 0

There are some aspects of reality one cannot translate into physics.
• 1 0
For me the problem is that if you want good suspension you have to buy a bike with top end parts to get it unless you part out your fork and shock to upgrade them. Now you have to get a 10k\$ bike to have Kashima coating, wich is a shame to me.
• 7 0
Psst, mate, don't tell everyone this, but the Kashima coating doesn't do anything.
• 1 0
Because Kashima is little more than bling. I switched my Kashima CSU/legs unit for a black version for aesthetics reasons, can't say that I noticed a difference.
• 1 0
@chakaping: It's just to say that now you pay 7-8k\$ for a bike and you still don't have the top forks and shocks. They come on bikes with top end groups.
• 1 0
@dhmad: you sound like the ideal candidate to build bikes instead of buying them complete. Not cheaper, but at least you get to choose where you put the money. Nice suspension, brakes and tires... and a Deore derailleur. No hard compound white label DHFs to sell off, no crappy grips, no seat you're going to change out anyway!
• 1 0
White label DHFs are the same as yellow label DHFs. You get to choose the colour when you order them OE.
• 1 0
@benpinnick: sure, I suppose that was a false equivalence. But even if it's an objectively good tire it's probably not *exactly* what the buyer would spec.
• 3 0
@dhmad: Fair enough, but the sentiment behind my response was that the mid-range options are often functionally indistinguishable from the top-end ones. What is annoying to me is when they out inferior dampers on a bike that costs multiple thousands of dollars or pounds.
• 6 5
I find the only people who complain about weight are those who don't train off the bike. I started working out a few years ago and it's unbelievable what a difference if made on my bike. I feel like my DH bike dropped 20 lbs. I regained a lot of the weight back when I injured my hip and it was a reminder how important training off the bike is.
• 4 1
Weight is weight though if you know what I mean. Put a weighted vest on the most athletic man in the world and he will jump and run slower. That's not a great example though because its not a weighted vest, it's something you have to move and manipulate away from your body, the lighter it is the more precisely and quickly you can do those movements.
A better example would be to take a 5 lb dumbell and try to move it in a circle with your arms extended, then try to do the same with 8 or 10lbs, it may only be 3-5 lbs but it will feel very different.

With that said I get what everyone means here and why there is such a resentment towards weight arguments. It's somewhat ridiculous when people are arguing over a hundred grams that may noticeably effect the quality of the bike in a negative way (rotors or cranks or something idk). I just think if people truly don't think weight doesn't matter they are fooling themselves because if you've ridden two bikes back to back that are the same other than 5lbs of weight, it's pretty obvious. Weight matters, it's just that function and practicality almost always matter more (not to mention \$\$\$).
• 1 0
@michaelandk2: I have 2 bikes. A 38 lb commencal supreme and a 30 lb full carbon specialized Enduro. I have no problem handling either bike and I don't notice the supreme being noticeably heavier than my Enduro while in riding. The only time I do notice is when I'm lifting my bikes on to the tail gate. No offence, I'm not trying to be rude but it sounds like you don't train off the bike. I used to think the same way as you until I started training. Try it and you'll see what I mean.
• 1 0
Hah well, at times I’ve trained more at times less. Right now I’m reasonably “fit”. I can run a sub 60s 400 while weighing 195 which isn’t easy for a 31 y/o .

@ThunderChunk:
• 1 0
However when you do lighten the bike, your legs can definitely feel it and you can feel the instant speed increase when climbing. Albeit, an small incremental increase and very short lived experience as your legs adapt to the new weight or setup, however it is something that is addictive to chase. Basically the weight weenie effect.
• 4 0
"You Shouldn't Worry Too Much About" anything in the MTB world, it is a recreational activity for F&^% sake.....
• 1 0
29 x 27.5 The rotation is less in a linear proportion with the increase of the wheel. However, the gyroscopic effect comes from the conservation of the angular momentum, which in turn is directly proportional to the wheel's moment of inertia, and the moment of inertia increases with the square of the wheel's diameter. Even with the smallest rotation, the gyroscopic effect of the wheel is greater.
• 2 0
@seb-stott I just got my privateer 141 built up. Its a tank in the stand and when pulling it off the car but dream on the trail. Heaviest trail bike I have owned, and Ive been on alu Konas for the last few years!
• 1 0
Lucky you! I've got my 141 arriving in a couple weeks (absolutely itching to get it!!!!) but was worried about the weight of it. Good to hear you don't seem to mind it too much.
• 1 0
Well done man, glad you got into the details of unsprung mass, rigid portion of sprung mass, and our connections to the bike. All make for an extremely dynamic condition as far as determining system stiffness and solving vibration problems. Fun stuff.
• 2 0
Would like to see the comparison calculations regarding unspung weight with a standard bike vs. a gearbox bike. Considering the weight of the cassette. Albeit that the cassette is in the middle of the wheel.
• 1 0
In general I'm on board with the line of argumentation. I do think there's a danger though of sending the message that if it's heavier, people will buy it because it's more durable and somehow better. I'm thinking of the early 2000s (evil imperial, banshee morphine, brooklyn machine works). If everyone says weight doesn't matter, there will be more commencal meta and specialized status type frames. Why bother to do FEM analysis of your design or source different alloys if everyone's fine with 6061 straight wall tubes?
• 1 0
if there’s anything i’ve learned in mountain biking thus far, it’s that marginally different #s, while not the end all be all, are definitely felt on the bike more than one would thing. a degree less here or there, a centimeter reach difference, 5mm more of bb drop or chainstay length, .2” wider on maxis rubber. all things when changed in their own won’t change your experience drastically, but can be felt on the bike. a 1% increase in acceleration, for me, is noticeable enough that i decide to take my shorter travel bike out more often. i may be in the minority though, and i will admit trading out my dhr/rekon combo to a dhr/dhf has made descending a whole lot more fun.
• 1 0
One counter-argument in favor of lighter bikes that wasn't directly mentioned is the handling in tech and 'tricks'. A lot of the ways we maneuver a bike in technical sections and for doing tricks (manualing, wheelies, bunny hops, pops, endo's etc) are all about leveraging your rider weight against the bike's weight. The bigger the ratio of rider/bike the easier it is to move that bike when doing these moves. Again, small marginal gains won't make a huge difference, but it is noticeable when you shave a kilo or so off of a bike.
• 1 0
Interesting topic, however find these articles often miss the point though. Was same with the idler topic. Context is king!

You can't cherry pick the parts that support one part of the theory and skip the rest because it doesn't fit or is too complicated.

Either ride your bike because it's fun, whatever bike you have (light/heavy/cheap/expensive/fast/slow).
Or
Ride against 'the clock' and it will tell you what's fastest.
• 2 1
"One other thing to note is that the rotational kinetic energy of a wheel doesn't depend on its radius"

Doesn't that also mean 29ers don't carry more momentum just because they're bigger...

"This means that if you had a 29" wheel/tire that weighed the same as a 27.5" wheel and tire, the acceleration would be the same. Of course, a like-for-like wheel or tire will be heavier in 29", but only by about a hundred grams or so."

... they carry more momentum just because the wheels are heavier.
• 1 0
I think if we claim weight doesn't matter we may be underestimating how much acceleration is done on mountain bike.

This is an extreme example but I was recently riding with my son on the shotgun seat up a reasonably steep climb, and anytime my cadence would drop a little too low it got much harder to pedal. That's not only because I was below the optimal RPM range for making power, but also because the bike would slow noticeably between each pedal stroke and every push was accelerating us again. The extra 30lbs on board make that painfully clear.

I'd also chime in with the others that wheel/tire weight makes a super tangible difference in feel. Whether or not it affects your speed, the weight of your tires can really change your bik's manners. Traction and flat protection are obviously higher priorities but lightness is fun!
• 3 0
Yeah, strap even a 10lb weight onto your trail bike and go for a ride. It's oppressive. Oh, but it only increased the "system weight" by 5%! But it decreased my pedaling pleasure by 75%.
• 1 0
So, buy a steel frame bike with midrange drivetrain, high quality suspension and brakes, and perhaps carbon wheels. Don't bother with top shelf drivetrain and carbon frames...waste of money. UNLESS you're a sponsored or otherwise very serious XC racer, then that 1% benefit will actually pay dividends since the podium finishers are all just seconds apart. For the rest of us, buy carbon because it's cool if you wish, otherwise just invest the time and effort in riding your bike to drop some pounds from your midsection you'll be far happier and have to spend a lot less money to make your overall riding weight lighter.
• 1 0
My tcx sx with 40mm tires climbs soooo much easier than my top fuel 9. My top fuel 9 climbs sooo much easier than my farley 9.6.

I dunno… is it tires? Frame?

Im willing to be a 2” tired carbon hard tail at 20lbs would be a rocket ship uphill. Absolute trash on the downs.
• 1 0
Quality article from Seb again. Always a good read.

I guess my take from it is, you would be better off spending money in to skills lessons, and or fitness training. You'll get more than 1% speed from both easily.

That or chuck the money saved in to some investment and just buy an ebike in a few years...?
• 1 0
Cool read. Appreciate the time and effort put in. For me, when you start talking about 3-4lb difference in bike weight, especially when some of that weight is in the wheel/tire combo there is a very noticeable difference in fun factor on mixed-terrain trails. I suppose it's all relative though to some extent. A strong 220lb rider on a 33lb trail bike might be equivalent to a lean 170lb rider on a 27lb trail bike. My wife and I both work out; I can run downstairs and do some curls with 35lb dumbbells and that's no big deal; for her that's rough to even get a couple reps in. All relative to some extent. But with equivalent riders? Lighter is more fun IMO.
• 1 0
The general point here is good, weight deserves less attention than it gets. That said, it matters far more than just the math here would suggest. First, measuring the importance of weight savings as a percentage of system weight is an odd metric, it suggests making your bike heavier matters less if it's really heavy. What really matters is how bike weight affects your watts per kg. This only really matters when applied to some objective. If that is to keep up on your local group ride, the real question is how much extra power can you produce over your friends at your normal pace. That's your budget. Spend it on heavier stronger parts, sticky tires, an idler, whatever. Once you've spent it, you'll be watching rear wheels ride away from the pain cave. Either that or find slower friends. We can sum it up in a concise theorem. A rider's bike part budget will be inversely proportional to their surplus power budget.
• 1 0

I'd point out that a good portion of the rider weight is basically what powers the system - mainly muscles - wheras the bike is "dead mass". The same way you could argue that ride weight does not matter when climbing if you only add muscles. Which btw would also be wrong as a bodybuilder type might be good at sprints but not on usual mtb tracks.

Second thing is that there is much more then purely weight what drives the efficiency of a bike. From geometry to weight discribution and the characteristics of different materials regarding flex etc. (carbon). Not to mention the effects on how a bike handles.
Even downhill bikes got a lot lighter during the past 10 years for a good reason.

I would argue that most riders benefit more from the handling of a lighter bike than from more reliable parts. With my 72 kg naked I have actually never had problems with lighter parts (not super light). Might be different for heavier riders but looking at e-mtb the current parts can take a lot of force/abuse even the top range / light parts.
• 1 0
I've been past week to the Bike Festival at Riva del Garda in Italy.
I've tried 7 different bikes on the same track, recording them with my Garmin.
It's clear that on the road a lighter bike is faster.
Off road it's a mix, a light bike and good suspension is the more efficient. For example the Spark 910 is light but the suspension is too active in trail mode, so the front lifts and it's difficult to have grip on the front.
In the descends the minimal packaging is a real trail bike (not the Spark 910). Bigger bikes are adapted to bikers that are really fast and need a strong bike. Personally with these bigger bikes like the Propain Spindrift, Ghost Riot EN, I was slower compares to my Propain Hugene 2019.
The new one is really better, no bobbing, more sensible suspension, light and funny. For trail bikers like me it's the top.
• 1 0
Honestly, instead of theoretical math, this deserves some Bro science.

Get a bike, time it up a chunky climb using a power meter, then start swapping wheels, tires, adding weight, and so on to test the actual results. Of course the power meter is a large part of the story, but adding 3#s to your fork for instance will likely result in extra upper body exhaustion even if it barely registers on the power meter/ stopwatch.
• 1 0
Better yet: as opposed to just a short trail, make it a 20-30 mile segment, at high altitude. The cumulative impacts of weight and excess rolling resistance get worse and worse as people fall apart physically.
• 1 0
@LeDuke: Well, it's not our time or money so why not?!
• 1 0
The only thing slower than a “heavy” bike is pushing a broken bike. So if you ride rough terrain, rock those DD tires and Cushcores. Go for the longer travel option when you order a bike (and hopefully get it someday).

If you race elite XC and you’re getting results (and no sponsor) get a sturdier second bike (or at least some beefier wheels/tires). Otherwise, if speed is what you seek, hire coaches for skills and training and get a powemeter. Get under 10% body fat. If you can’t easily send 2m (6ft) drops and put out sustained 5w/kg climbing, a light bike is just a colossal waste of money.
• 1 0
If I'm not racing then weight doesn't matter but if I'm racing 20sec lost for every 30 minutes of riding is a lot. Also I think racers are just starting to realize how much energy they lose by absorbing bumps / maintaining control. This aspect is being studied for all kinds of racing, not just bikes.
We are starting to see more success by coasting through rough sections instead of sprinting through the bumps then braking hard for the next corner. Pedalling the smooth line instead of pedalling through bumps then using that saved energy to pedal hard on the fully smooth sections or to absorb a faster line in the rough non-pedal downhill sections. Light bikes helps with bike control
• 1 0
Yes, and no... I just picked up an Ibis Ripley AF, which Jenson weighed at ~32.5 lbs, and I love it! Would I pay a couple grand more for the lighter carbon version? No, I would not. But would I have chosen a 34+ lb trail bike to save a few hundred bucks more? Also no. I think one has to draw the line somewhere, and weight does matter (to me) --along with many other factors...
• 1 0
It seems most affordable bikes nowadays weigh around 35 lb. A good weight for a bike IMO is 25 lb.

Hardly a 1 kg difference.

(And the equations in this article miss the rotational energy associated with wheels. Heavy wheels are a bigger deal than other heavy parts. And in addition to obvious weight issues, they also have gyroscopic effects.)

But all things said, losing weight off your belly is far better than paying to drop weight from your bike.
• 1 0
"A good weight for a bike IMO is 25lb"

Mate, that's a good weight for a mid-range XC bike these days.

With 29in wheels and the stronger tyres and forks we want on our longer-travel bikes, 32lb-34lb is a good weight - and 35lb is quite reasonable for an entry level bike or a heavy duty enduro bike.
• 1 0
@chakaping: "Mate, that's a good weight for a mid-range XC bike these days."

And those bikes are WAY out of the common folks' price range. They also have geometry that's too aggressive for most real-world riders.

"Good weight" isn't determined by what is available, it's determined by what actually complements the rider. For someone who's 6'3" 220 lb, 35 lb is one thing. For a 150 lb rider who doesn't need a bike to be bombproof, (or even worse, for a 5'3" 110 lb woman) it's completely different. For me, the ability, ease, & comfort of moving a 25 lb bike beneath me compared to a 35 lb one is significant, and the heavier bike is less fun to the point that it's not worth buying--I'll stick with the old school bikes.

The industry makes premium bikes for racers, for rough terrain, jumping, etc., and the low-end bikes are just cheaper versions of the same thing. Bikes are WAY more stout than they used to be. Big wheels mean everything else gets heavier, too, especially to maintain consistent rigidity. And the same goes for longer travel suspension. All that adds up, and that's why to get lightweight, you have to pay through the nose.

And that's the problem. Not every bike needs to be a Raptor or a Corvette. A Miata is not only perfectly viable, it's actually MORE FUN in most cases despite being slower. That's the hole I see in today's market. I believe for the skill & interest of the majority of riders (and potential riders), and for the intensity that they will actually ride, a simpler, lighter, smaller, less-travel, less aggressive bike would be more entertaining, engaging, and rewarding for them, and you can still get them to pay a mild premium for it.
• 1 0
I'm sorry to say you that your calculations for the wheels' rotational energy are wrong. The formula for kinetic energy it's not the same for rotational energy. To evaluate the rotational energy, you must know ho to work with Moments of Inertia.
I have a channel about bicycles and I dedicated a whole video to find out if the weight on the wheels is so meaningful, and it isn't, particullarly at high speeds.
The video it's in Portuguese, but has English subtitles. Here's the link:
• 1 0
But what's the deal with that oval rear wheel in the last photo. Maybe the parts of the rim and tire closer to the hub are reducing the amount of energy needed to accelerate the wheel. Is this the new thing for racing?
• 2 2
Replacing the air in your tires with helium will make you faster.
Putting lighter oil in your shock and fork will make you faster
Riding naked ( less weight) will make you faster
Ti water bottle bolts make you faster
Drink water with the heavy water molecules removed will make you faster.
Lessons will make you faster but don't distract from the \$/g/speed thing... this is actually the most efficient as g=0 so benefit is infinity...sorry no math...

Loved the nerd out, I am a gram counter on my gear and get great joy from having the perfect \$/g/speed for me.
• 5 0
Deleting the photos from your phone before a ride can shave off a significant number of picograms.
• 2 2
My Pro Mate always said stop spending all that cash on light weight components, he said look in the mirror and ask yourself how many Kg you can loose that will be allot healthier and cheaper to achieve and you’re be shedding a load more weight too!
Love the debate we all love to geek out on the cool parts etc… but we never really look in the mirror!
Cheers
• 1 0
Negative Tokyo-bakka. No weight too lose here. Unless I give up beer, pastries, etc. That's out of the question!

Ps. I'm actually 9.5% BF atm.
• 2 0
Assuming you can put out the same amount of power, the least expensive method method to obtain a lighter bike is to cut the weight of the loose nut ON the seat. ;-D
• 2 1
The main place the weight makes a difference is on the sales floor.. As a salesman, I can tell you all about how much better brakes are or an upgraded damper, but weight is the first thing a person can really feel..
• 1 0
The bike industry has taught people to obsess about bike weight. Nobody wants a 40 lb bike, (e-bikes are selling like hot cakes), but sure, a light bike sure feels exciting...
• 1 0
@Zhehan: very true. But, most of us really don't notice a pound on the trail.. Where you take the weight off makes a difference for sure.. I know I'd be better off dropping 20lbs off my body vs. a pound on my bike..
• 2 0
This is why my "trail" bike has DH tires and cushcore. The performance downhill outweighs (heh) the minor sluggishness it adds to the uphills.
• 2 0
so if i understand this correctly , go on a diet and stop drinking beer and then i can ride a heavier bike and still be better off ?
• 2 2
There is a performance issue too. My 230lbs on a 37lb enduro bike can smash down anything at speed. Nothing gets in my way (except the odd tree). Smaller riders on much lighter bikes get bounced around a lot more. If I need more traction I just lean and get leverage to force it. Smaller riders can't do that. That being said I'm actually not a smashy rider but I've never had a "regular" bike survive much. A 30lb bike it unthinkable to me unless it's a gravel bike.
• 4 0
I'm conflicted... All this makes a ton of sense, but, well, Dangerholm.
• 2 0
Maybe have a lycra rider/racer write the next story on this. Seems like every time this comes up, the editorial is "drunk on their own wine"
• 2 2
I'm guessing in the end, we should all be riding fancy Aluminum bikes but with sick wheels (can complete Alum bikes ever come with sick wheels please??), tires and suspension rather than expensive frames and crap components. Likely be about the same price, similar overall weight, but ride hell nice and not have to worry about breaking carbon etc.

Especially since Geometry and bike length has hit its extreme and even snapped back a bit (e.g. the new Capra). You could theoretically keep a bike a long time with some upgrades and be good!
• 1 0
Just a simple example, coasting down jump line on regular bike requires me to pedal not to case jumps, on bike gram the brakes not to overshoot to flat within 15 lb difference only;
• 2 1
Never worried about bike weight ever... I love those who count ever gram on their bike to make it light and sick, then you see them on trail and they walk obstacles on blue trails lol
• 3 0
Every morning I worry. Does my ass look fat in these pants . Weight matters.
• 1 0
No, your ass looks fat because it is fat, not because of the pants.
• 2 0
@JohanG: you be sleeping on the spare bed tonight. And I'm going shopping with your credit card !
• 1 1
Would weight really hurt pumping? Isn't that another case of the rider weight being a much more significant part of the system? Plus, what goes up must come down, so although the up-pump might take more energy with a heavier bike, that added potential energy is gained back on the down-pump.
• 2 0
Try shifting a heavier weight at highest speed in the gym and then do the same with a lower weight. Think that would answer your question. Look at BMX as another example. They use very light bikes, but there is a lower limit to how they want a bike to weigh otherwise it doesn't 'feel' confidence inspiring.
• 1 2
@IOMHENDO: Lifting a weight is terrible analogy to pumping a bike. Try rolling a heavy ball through a pump track. You have to do work more on the first up, but it will run away from you on the next down and then carry mostly to the top of the next roll, and then requires just a bit of a push. A lighter one would take less effort on the first up, but won't go as far up the next one.
• 1 0
DH Minion on my Reign was way slower than EXO. I'm surprised to hear that it was rolling resistance that made this difference, vs weight in the same tire with different casing.
• 1 1
Gotta love all the comments that I'll sum up as "replaced my tired 10 year old bike with a brand new one that was 1kg lighter and the difference is amazing!"

Well, yeah... might be something other than the weight of the bike, son.

Try this: go for a ride with an empty 20oz water bottle on your bike. Then fill 'er up and do the same ride. Better yet, have your wife randomly fill or not fill the bottle (don't use a transparent bottle) a few times.

Can you tell? No, you cannot.

There is actually lots of good research on the "just noticeable difference" though as far as I know nobody has studied it with bikes. If a 1% difference (all other factors like frame geometry/parts/travel being equal) is perceptible it would be... quite a finding.

-W
• 2 0
Don’t like bikes that are less than 28 lbs. never have. They don’t feel as stable. My bike is around 30 lbs and I can knock weight off but as is, my bike is bulletproof
• 1 0
25 feels a bit heavy to me. I have 3 full sus bikes, all under 25lbs. 2 trek fuel 9.9's, 1 Scott spark rc. The Scott is under 23lbs, and feels a little sketchy in the rough. 23-24lbs feels like the sweet spot.
• 1 0
I think the weight issue is underblown. A lot of reviews don't mention it at all or just goes about defending the weight with "it descends well". It's not even impressive if it decends well if its a 15kg near-DH bike.
• 22 22
If weight isn't important stop mentioning it as a key factor in reviews. The reason consumers are obsessed with something is largely down to media; so maybe this should have been an internal article.
• 9 0
It's an important metric but not the most important. Could be a deciding factor.
• 9 1
• 16 4
Reviews are written for the readers and readers want to know how much the bike weighs. Also, I'm not saying it isn't important, just less important than it's often regarded to be. It takes two minutes to put a bike on a scale and write the weight in a review, so I'm going to keep on doing that.
• 4 0
If two similar items have the same performance, same price, same quality but one is lighter then weight can be a deciding factor. I'm pretty sure most reviews have weight as the last thing they list.
• 3 1
If weight is not mentioned people will complain.
• 1 0
Reviews are just an accounting of the attributes of a bike. Individually, any one of those attributes might not be overly important, but cumulatively they make the bike what it is. Weight is similar to any other attribute in that regard.
• 2 1
but it is important. If two bikes are the same price, and descend the same, but through a combination of better frame engineering and smarter spec choice one bike is lighter, well the lighter bike is the better bike. The article goes into depth on price vs weight and capability vs weight but ignores that some spec and frame choices are just overbuilt boat anchors that offer no benefit for the intended use.
• 5 0
Disagree. Weight is really important. Otherwise how is one supposed to make an objective comparison? For example you might say horsepower is unimportant, just look at torque and power to weight. People would still need a horsepower number to make a complete decision when buying a car.
• 1 0
@toast2266: True, but PB pretty consistently calls out the same handful of attributes in the little sidebar on a bike review. Travel, weight, head angle, and chainstay length are almost always in the sidebar, implying that PB thinks those are some of the most very important stats.
• 2 0
@justinfoil: sure, but are they wrong? I'd say, of the quantifiable measurements on a bike, those are all pretty important for how the bike rides.
• 1 1
@toast2266: Chainstay length is almost useless without wheelbase or front-center, head angle is also almost useless without reach or wheelbase or front-center (compare to old DH bikes with 63 degree HTA but tiny reach, ride totally different than modern bikes), and of course Seb has just shown that weight isn't that much of a big deal.
• 2 0
Yes, ratio bike weight / total system weight should be taken more into account.
• 2 1
This is great, and the main reason I was so glad to see Seb Stott join pinkbike. He truly shows the madness around believing a bike who’s a little heavier should be slower.
• 3 0
is this bike fat shaming ?
• 1 0
Some bikes at 16kg would feel good,other at the same weight are crap. IMO how a bike feels it more about overall package and suspension/geometry than weight itself.
• 1 0
I just wanted to say that I appreciate you accommodating both the US and UK crowd by using the term math(s). Never understood why the UK pluralizes the word.
• 1 0
Is math short for mathematic? Or mathematics? Hope the penny has dropped now. Or the cent, if you prefer.
• 1 0
@chakaping: the pound?
• 2 2
In my personal experience, rolling resistance and rider fitness matter the most, versus bike weight. Within reason of course. But, 2 lbs. of bike weight isn't going to matter in the grand scheme of things.
• 5 0
I can't disagree more, once you hone in your fitness, that 2 lbs is big a deal on mountain bikes, unless of course all you do is use lift service.
• 3 0
I can notice a half a pound difference on my bike. Albeit small, but noticeable. Over the course of a long ride, it can make a big difference.
• 1 1
@tacklingdummy and mrkbb: www.theproscloset.com/blogs/news/the-weight-equation-how-important-is-a-light-bike

www.velonews.com/gear/tech-faq-does-bike-weight-matter

Here are a few examples from a quick Google search. If you are already small, super light and in excellent condition, bike weight will matter some, but not that much. I just can't see how 8oz/200g of weight makes a big difference. If I was 5'4 and weight 112 lbs, then maybe I might notice something like that. Of course, there's the placebo effect of knowing your bike is lighter.

2lbs/1 kilo of weight in the overall system of rider + bike + load weight total doesn't matter for most people. If a rider weighs 200lbs and their bike weighs 27 lbs., plus 5 lbs. of clothing/shoes/water bottle etc., we get ~235 lbs. 2lb / 235 lbs. = .00851 or 0.851% total weight. That amount is statistically insignificant and will not matter. Downvote me all you want,
• 1 0
@Zhehan: I am not basing my opinions from a Google search. I am basing my opinions on over 15 years of real world mountain biking experience. Riding a ton. I'm 5'7" and 135 lbs. Trust me I notice a difference of 1/2 pound. Added bike weight is different than added carrying weight. Added bike weight is more noticeable to me. However, I do notice small changes in weight like riding shoes. Try riding in shoes that are 100g heavier per shoe. You will notice it on the climbs you do regularly.
• 1 0
@Zhehan: You can easily notice 1 lb difference in a wheelset. As to your argument, it all depends on what you want to get out of your bike. If you have two riders, same fitness, same skill, but one has a 2 lbs lighter bike than the other, guess who will get up that hill first at same watt output? I race, for me every half pound counts. It all ads up in the end. Just carry around 2 lbs for 2 hours and I bet it will feel much heavier after those 2 hrs then it did when you started.
• 3 0
Beer and burgers all the way! F*ck the weight!
• 1 0
The link you provided for your physics directly contradicts your stated position regarding acceleration of wheels of differing sizes that weigh the same.
• 1 0
Calls out bro science on a previous article, gets a full well thought out article in response. I appreciate and respect this. More of this please…
• 1 0
Id rather buy cheaper heavier bike and spend remains part for lift assisted trip, comparing to the light xc bike that should be pedaled uphill
• 1 0
All the weight justification is funny. It’s like asking if wagon wheels are really that boring? If you’re also boring, not at all.
• 1 0
Don't worry about weight. Unless it's the new transition ally mullet, what ever name it is. That thing is amazingly heavy. Too heavy.
• 4 4
Yeah, weight doesn't matter but that recent PB promotion for the ebike with the same weight and price as a regular bike has been a total game changer in my riding experience.
• 2 0
Yeah I was gonna say that.
• 1 0
Wow, a very interesting read! In-depth review of chain lubes coming soon? Pretty please?
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I love my heavy E-bike it is so much more stable especially for jumping, and going down hill it is like a run away train.
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Gravity got robbed!!!
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Good suspension design>Bike weight.
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For some reason, ive felt that riding down with my 23 kg ebike is much nicer than my older 14 kg carbon sentinel fully decked out. It feels calm, no matter what, doesent jump around when i hit a rock or rut, allthough I do miss the liviliness when you go down a more playfull track... ive said it before and ill say it again, after coming from the time of 20+ dh bikes, the only time you really feel the weight of the bike is when you lift it to put it on the truck...
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Doesn't jump.
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@littleskull99: ya right.
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Gonna be a run on bikes at Walmart, hope they still have a few with SLX
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I'm happy PB has a real science man now. Seb is too good for us.
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Thank you!!!!!!!!!!!!!!!! I've been arguing this for years!!!!!! Just forwarded to all my biking(real) friends.
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Mind blown... so I guess my 37lb Status isnt so bad after all, haha.
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Lawyers and Dentists that spent 12k on their new super light bikes (and cant ride for dogshit) are gonna be pissed!
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The bike/component manufacturers are going to like the insight of this post, but who cares.
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With an equal weight Diameter directly effects acceleration that day 1 physics..
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Shit a good amount in the morning and this will save you 1500€, because you do not need to buy that carbon wheelset.
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If weight is a minor factor, then why do professional road and xc riders all have the lightest bikes in the world?
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I don't think dentists care about science after work, just marginal savings trough ti bolts and carbon extras
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Same circumstances meaning same energy applied to both bikes
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Just wear lycra that saves weight
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and shave those legs
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but how to quantify this 1% gain in acceleration in seconds? impossible
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Very impressive analysis!
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"Let's say an average rider weighs 80kg"

Guys are people too...
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tl;dr

Off to buy some titanium bolts.
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I run 60psi. Does that make me fast?
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I can ride a light bike all day. Period. That is all I can offer.
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These are some pretty heavy theories not to be taken lightly.
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I'll take the light bike...
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heavy bikes make you stronger.
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C's get degrees, and jobs at PB
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Preach seb.
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Wrong
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You lost me at "maths".
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yo, it's just bikes.