It’s Time to Recalibrate Our Ideas About Chainstay Length

Oct 12, 2022 at 11:43
by Matt Wragg  
Photo Satchel Cronk
Photo: Satchel Cronk

Words: Matt Wragg
Photos: Satchel Cronk & Tom Richards


As reaches have grown, what we think of as "short" and "long" chainstays needs to start shifting as well.

It is no secret how chainstays affect the handling of a bike. Even a dry, technical document like the UCI technical guidelines states very clearly what a shorter or longer chainstays does. Yet to read the forum discussions and marketing material around them, you could be forgiven for thinking that there is some dark magic going on back there.

bigquotesIf the front or rear center is too short, this will reduce the bicycle’s stability whereas if the front or rear center is too long the bicycle will be less maneuverable.UCI Technical Regulations

As a whole, geometry’s evolution from old school to modern has not been a smooth-flowing process—it comes in drips and drabs. Take reach for an example. Mondraker drew a blueprint for longer reaches more than a decade ago, but it is only recently that we have been able to have intelligent discussions about it. I think Matt Beers’ recent editorial represents a growing understanding that reach isn’t some magic number for brands to compete over, but an actual functional part of bike fit and performance.

To understand the question around chainstays, you first need to fully understand what has happened to reach, and to a lesser extent, headangles. Yes, wheelbases got longer, but by how much? It is hard to find old reach values, if for no better reason than it was not a common metric on geomerty charts a decade ago. But there’s one bike I know, so I’ll use it as a benchmark: the original Ibis Ripley. Yes, it was launched in 2013, but Ibis were conservative even back then. The large had a 406mm reach and Mike Levy liked to tell everyone that all bikes should be like the Ripley. Today, the current large Ripley has a 475mm reach—a growth of more than 60mm—which is still on the conservative end of the scale compared to some brands.

Ibis Ripley. 2021 Field Trip. Photo Tom Richards
The current Ibis Ripley AF is a lot longer than its predecessors. Photo: Tom Richards.

Indirectly, this goes a long way in explaining the industry’s fixation on short chainstays. If your reach was 406mm, the diameter of a 29-inch wheel prohibits getting your chainstays short enough to even match the reach. With a bike this short, every millimeter shorter probably felt better, and this is how dogma emerges. Unsurprisingly if you add 6 centimeters to the front center of a bike, the overall balance dramatically changes. Balance is the keyword in that sentence—I believe the next big step for progress is starting to have sensible discussions around chainstay length and to stop using descriptors like “nimble”, “playful” or “snappy” around them.

I’m 1.75m/5’9” – an average-sized human, more or less. Last summer I was on a 29er with 465mm reach, 64-degree head angle, and 435mm chainstays. Coming off a few years of almost exclusively running longer-chainstayed bikes, the first thing I noticed was the weight distribution. Initially, it manifested as less weight on the rear axle, so less traction.

Photo Satchel Cronk
Specialized Stumpjumpers have two chainstay lengths, one for sizes S1-S4, and a longer set for sizes S5 and S6. Photo: Satchel Cronk

The first consequence of me trying to mitigate this was to hang off the back of the bike to keep the rear wheel traction at the level I was used to from my other bikes. Soon I began to realize that this tactic was compromising my riding because I couldn’t be off the back and put enough weight on the front end at the same time, so the bike started to understeer. Realizing this, I turned a few dials and had a little chat with myself about riding properly.

Pushing my weight forward brought the steering back under control, but there was a compromise again. With my weigh forward, there now was not enough weight on the rear wheel. I could feel it in every corner, I had to delay my exit just a little longer to let the back of the bike compose itself. If I tried to be aggressive and exit early, the rear would oversteer and break away. With the rear slightly unweighted like this, I was not getting enough feedback and it felt like it was going away from me without warning. Waiting like that in every corner felt like I was losing so much speed.

Maybe this oversteer is what people mean by “playful” chainstays? Certainly, it makes intellectual sense – less weight on the rear axle will make it easier to pull after you, although I am not convinced there is a benefit there.

In the past I had another bike that was doing something similar. It was a 29er with a 450mm reach, 66 degree headangle and 435mm chainstays. I noticed the front-to-rear imbalance, although since it was a shorter travel bike I noticed it more on the climbs when the rear would slip away from me under power. On that slightly smaller bike, I could solve the issue by adding 10psi to the fork and going from a 50mm to a 40mm stem. This shifted my weight backward and I felt much more centered on the bike and the bike stopped slipping out.

2021 Rocky Mountain Altitude
A flip chip on the Rocky Mountain Altitude allows for 10mm of chainstay length adjustment.

On the bike last summer, though, I was out of options. Maybe I could have found a 180mm fork, or tried a 32mm stem instead of a 40mm, but both of those came with downsides that did not appeal to me. Looking back, I wonder if dropping from a 30mm to a 20mm rise bar might have helped. Maybe there was more I could have done with the suspension? At the end of the day, my feeling is that if you have to go to those lengths to feel balanced, then there is a fundamental flaw with the bike’s geometry - a balanced bike should be able to accommodate a wide range of settings.

Photo Satchel Cronk
The Forbidden Dreadnought chainstay length ranges from 422mm to a whopping 464mm across its four sizes. Photo: Satchel Cronk

After years of experimenting, I now have a preferred minimum chainstay length – 440mm for a 460mm-ish reach bike, although I also have a 450mm chainstayed bike, and that feels even better. The longer stays seem to flex a little more, so the feel at the rear of the bike is superb. I cannot find a downside to running chainstays at that length, in fact, I feel longer chainstays help me be more playful with my riding as I feel centered and balanced on the bike. Talking to a few people about my ideas, I have yet to find someone who has offered me a coherent performance argument for shorter stays - I'd love to hear one.

Maybe what we need is a recalibration of perceptions? A few years ago 420mm was a short chainstay. Today it is 430mm, why couldn’t it be 440mm tomorrow? More interestingly, people like Seb Stott are starting to ask questions about what happens if we go even longer.

Implicit in all this is the idea of proportional chainstays. If there is a relationship between reach, head angle, and chainstay length, it follows that if you change one you will need to change the others. In the absence of a golden rule for proportion, how are bike companies going to make bikes that give a similar riding sensation at their smallest and largest sizes? Some brands do proportional sizing that addresses this by changing rear-centers along with reach, but most still don’t, and none offer a choice of chainstay lengths. Will the industry as a whole see the importance of balancing bikes, or will the sole chainstay model most brands have continue to prevail?


392 Comments

  • 456 7
 I think chainstay girth needs to be considered as well.
  • 137 3
 Some claim that it’s even more important
  • 72 3
 chainstay motion is critical
  • 20 2
 nah it's the motion that counts
  • 60 0
 i think most will agree its not the size its what you do with it
  • 8 0
 @Mntneer: I believe how you use your chainstay is most important.
  • 40 0
 I believe the ‘forestay’ to more critical than length.
  • 7 0
 Dont forget about chainstay yaw
  • 9 1
 @nickfranko: surely you can’t expect a paring knife to do the job of a machete
  • 21 0
 It’s actually the travel that’s important and how you use it, not enough damping leads to premature bottom out.
  • 80 0
 Is a 3” chainstay long?? Asking for a friend..
  • 11 0
 Length usually means harder chainslap.
  • 18 0
 @Mntneer: Don't call me Shirley.
  • 7 9
 I'm sure most PB users are from Reddit..
  • 9 0
 It's a Grow'er or a Show'er?
  • 9 0
 I heard that @kelleymtb guy doesn't even have a chainstay
  • 9 0
 @cursh1: I heard @kelleymtb runs chainstay implants.
  • 3 0
 With a proper warm up routine, you can get away with any size stay.
  • 97 1
 I've added over 1.5 inches to my chainstays with one weird trick.
  • 41 0
 @panaphonic: bike mechanics must hate you.
  • 1 1
 My chainstay is a chode. My bike is so retro
  • 4 0
 My chain stay grows the more excited I get
  • 3 0
 I've heard shape matters too. If you have the right shape you can hit the correct spot in your travel every time.
  • 4 1
 Gold. lol Well done PB.
  • 11 0
 People laugh and say my chainstays are short but it's just very cold where I ride ok...
  • 5 0
 Can we do something to enhance the performance of older bikes?
  • 2 0
 My girlfriend really loves the curve of my chainstay!
  • 1 0
 What if its personality is really good?
  • 237 4
 This is a bit curious. You report shorter chainstays causing less weight on the rear axle, when really, keeping all else the same, shorter chainstays will increase the weight on the rear axle due to its short lever arm. You also report the solution might be increasing fork travel or decreasing fork sag, both of which would increase the imbalance of a long front/short rear center setup (by stretching the front center). I think some more analysis might be required here…
  • 50 2
 Agreed. I think some of the characteristics Matt is feeling are in the right direction, but the logic/explanation is definitely off and there might be some placebo. Singling out one dimension on a bike in you rmind is damn near impossible, and I am not good at it either. I would like to see a more in depth approach to such a huge topic and huge influencer of bike design/ride characteristic.
  • 22 2
 I found that weird too. Maybe on the downs it's the case, but on the ups I find you're more weighted on the rear wheel so traction is better. My newer hardtail is about 20mm longer out back and I lose grip on the back wheel way easier when out of the saddle. If the stays are short your body should be right over them.
  • 22 3
 he also said that needing to change bars/stems or adjusting fork travel meant the bikes geo was "fundamentally flawed"...???? WTF I don't think I've ever owned a bike I didn't swap out bars and stems multiple times to get it to fit right.

Maybe the OP needs to buy an Atherton so they can spec exactly what geo they want???
  • 12 0
 This is something that stood out to me as well. If all other geo is fixed, lengthening the wheel base (WB) by increasing reach and keeping the chainstay/rear center (RC) length constant, results in an increase in rear bias (RB). Given by the formula RB = 1 - (RC/WB). From this is can be seen that reducing the chainstay length will also increase rear bias. This can also be seen in making a spring rate calculation for 2 bikes with same RB value and differing wheelbases. The longer bike will have a higher recommended spring rate than the shorter one for a rider of the some weight. This is one of the many factors that is probably contributing to why many complain that many of the simple online spring calculators give too low of recommendations.
  • 14 0
 I wonder if Matt likes to maintain a relatively static position over the BB. I find subtle weight shifts is all it takes to maintain even tractions in flat corners no matter what the static front/rear centers numbers are on my HT with 422 RC & 690 FC or 160mm travel AM with 436 RC & 795 FC. The front center always gets shorter as the fork compresses and the rear is fairly static so maintaining a dynamic position.is necessary no matter what the static numbers look like.

"More analysis might be required here"
  • 18 2
 I've noticed traction is about how you use your legs more than anything. If you just stand there and let the bike do the work, sure, it's more about the geometry. But if you ride actively, you actively generate traction where and when you need it by pushing and weighting your arms or legs...
  • 29 0
 Thank you, I was scratching my head the entire article wondering what he was talking a bout. I've ridden bikes with 415 to 445 chainstays and my experience is the longer you go the less weight there is on the rear axle but the more balanced the bike feels. Really, longer chainstays have more effect on the front of the bike because you don't need to weight it as much as you do when the chainstays are super short.
  • 2 0
 @vitaflo: I'm curious about the longer stays weighting the front wheel? How does that work?
  • 22 1
 @Svinyard: Imagine a bike with EXTREMELY long chainstays, like 100 feet long. The back wheel would have very little weight on it other than the weight of the wheel itself, plus a little tiny bit of leverage from your body weight. This would cause your front wheel to have like 99% of your weight on it, even if you have a "long" reach of 500mm. Same rule applies on a much smaller scale for longer chainstays, it puts more of your weight through your feet on the front wheel and vice versa with short CS.
  • 10 0
 @misteraustin: Or conversely think of a bike with 0mm chainstays with the rear wheel axle directly attached to the BB (a flipped Penny-farthing). All of your weight would be on the rear axle and none on the front. You would have to shift all your body weight to the front of the bike, increasing that amount as the front center was increased.
  • 4 2
 I think you guys are confusing front center, wheelbase and reach… if you slacken a head angle or put on a longer travel fork, the reach shortens, conversely the wheelbase increases so what are you referring to as the front center, wheelbase or reach or what?
  • 5 1
 @SonofBovril:I was talking about front/rear center not reach though you are right about head angle & reach affecting front center. BTW, a slacker head angle doesn't effect reach unless you use a longer fork to achieve it.
  • 5 2
 sounds like he needs a stronger core. You can't solve everything with a longer bike. Also most people can't even bunnyhop a log en todays bikes! Is playful just more weight on the front so easier to scrub and drag the rear tire?
  • 3 3
 @bikeracer28 what I interpreted Matt's description of ' less weight on the rear axle' , is pressure on the rear wheel through a corner. A longer chainstay is a longer lever on the rear wheel, creating more pressure in a corner, this counteracts over-rotation (oversteer).
  • 2 1
 I learned to hate short stays from all the wheels I broke because of my weight over the rear axle
  • 5 3
 @Joecx: If one has an adjustable headset it certainly reduces reach. It’s pretty clear when I adjust my bike to the slackest head angle my handlebars are now closer to my saddle. Am I missing something?
  • 2 1
 @SonofBovril: Draw a segment between the two contact patches of the front and rear wheel. It's the wheelbase.
Now draw another segment, from the center of the bb shell perpendicularly to the ground.
It will bisect the wheelbase in two, the front center and the rear center.
  • 2 1
 Was going to post along these lines, not saying that he's wrong on how the bike feels but the physics seems to be off
  • 5 0
 I totally agree, i was a bit confused by Matts analysis.
I have a Commencal Meta with 63.5 HA, 495 Reach and 433 Chainstay, so i have pretty much the shortest chainstays possible in relation to the rest of the bike. I thought a lot about rear to front center balance, and of course, the short chainstays mean that you have about 2/3 of your weight on the back wheel, while the front is relatively light.
This is very noticeable while riding, you really have to weigt the front and adapt a very aggressive position, especially on mellow terrain. Otherwise the front easily washes out and you dont get good front wheel grip.
I countered this to a degree by increasing sag in the fork and decreasing sag in the rear, so that the weight distribution at sag is a bit more front wheel heavy.
I would think that increasing pressure at the fork for less sag like matt suggests would have the opposite effect.
I guess his thinking was that more fork sag means more reach, but we are talking about wheelbase and front- to rear center ratio here. With a slack head angle the shortening of wheelbase and front center as you go through travel is a lot more substantial than the increase in reach.
  • 7 3
 @Chondog94: Its the other way around actually. If you slacken the bike with the same fork, your stack (height of the headtube) will drop of course. Reach, BB and headtube form a right triangle. If you "drop" this triangle by a couple mm as you decrease the HA and lower the headtube, the upper part of the triangle, the reach, must grow.
Your handlebars might still be closer to you, especially if you have a lot of spacers under the stem. As you slacken the steering axis, the stem is pointing more backwards and with some spacers, it might actually come closer to you. but this does not affect the reach measurement, as it is taken on the frame and determined by the head tube, not the actual place your handlebars are at.
  • 2 0
 @jesse-effing-edwards: I think it's all about where the vertical of your COG falls in relation to the rear wheel's contact patch. If it falls within the contact patch, it will increase static friction, while if it falls outside of it will increase the slip moment. So besides reach and chainstay length, effective seat angle plays a key role here, since your COG would definitely be between your bellybutton and your hips.

Matt's statements also do make more sense in relation to HIS riding style and preferred wheel size. A 420mm chainstay length is still both playful and stable in a 25.7" wheeler bike.
  • 26 0
 @SonofBovril: front center is horizontal distance from bottom bracket to front axle.

So many words in here where it's all pretty easy to summarize:

1. Around 2017 everyone started noticing that more front center (more reach and slacker head angles) and getting the hands further behind the front axle made bike more stable and less prone to OTB events.

2. The increased above started making seated cockpit lengths too long (even with shorter stems). Seat angles got steeper to compensate. Turns out that on steep uphills this also compensates for rear suspension sag which in many scenarios improves climbing overall.

3. Once the dust settled on the front center increases it was noticed that weigh balance was compromised. Chainstay lengths have started to increase in proportion.

That's it.

The more interesting discussion is what are the tradeoffs of these "improvements"? Is more always better?

The obvious answer: It depends.
Where articles like this seems a little wierd is they make the assumption that these changes are universally better no matter the use case or riding style.
  • 3 2
 Yes. His overall observation may be correct, but his analysis is off…
  • 2 0
 @Chondog94: there was a large debate about this in an article about some adjustable headset a while back. I was initially on your side. Somebody jumped in and said I was wrong, it doesn’t (significantly) affect the reach. I ended up doing the math and changed my mind, finding they were more right.

The rearward movement of the handle bars with the angle adjusting headset in the slack position causes the reach to shorten, but the rotation of the bike downward, due to the reduced stack height, counters this and you end up with values very close to where you started: a couple millimeters, it varies depending on the rest of your frame geometry. In my opinion it is basically negligible.
  • 1 0
 @levaca: The increase in reach might also help by forcing you to be slightly futher forward on the bike, but I believe the biggest difference when increasing front sag and decreasing rear sag comes from the change in dynamic grip provided by the suspension when riding rough terrain. The front tracking more while the rear skips more shifts the balace to a more oversteery bike.

On smooth terrain the only advantages to changing sag in such a way will be the geometry shift, because the dynamic grip is then irrelevant.
  • 1 0
 @levaca: Thanks, makes sense. Interesting. I can definitely feel the closer handlebars when I adjust my head angle, my “cockpit” feels more compact and closer to my chest which will effect the way I ride.
  • 4 0
 @KennyWatson: You need to also consider that the dropper post enabled all of this. Today's bikes require that you have space to move around between the axles to work well. I'm sure people would have figured out the "over the bike" descending geometry earlier had droppers been ubiquitous 20 years ago.
  • 2 0
 @Chondog94: Do you also roll your bars a little forward when doing this adjustment?
  • 3 13
flag KJP1230 (Oct 15, 2022 at 12:04) (Below Threshold)
 An entire thread of people who are confidently incorrect. Longer chainstays = more force into the contact patch of the tire. This is basic physics. Longer levers exert more torque against the lever axis as a function of increased length or force (or both). If the force remains the same (i.e. the % of body weight transmitted through your feet as a function of riding position), the longer the chainstay, the MORE torque (realized as force in the tire contact patch) you will have as the lever (chainstay) gets longer.

This is the reason my elementary school science teacher could lift his car in the parking lot by building a long wooden lever, placing the axis near the car, and using his body weight at the end of the lever arm.

Don't believe me? Try it for yourself. Go sit next to a door and push that door open either from the inside (hand near the door hinges) or on the outside (hand near the handle). Your hand position near the handle will require MUCH less force to move the door.
  • 2 11
flag KJP1230 (Oct 15, 2022 at 12:07) (Below Threshold)
 @misteraustin: You've been upvoted, but you are entirely incorrect. The longer the lever (chainstays) the MORE torque is applied (force) at the end of the lever.

Archimedes said it best, "Give me a lever long enough and a fulcrum on which to place it, and I shall move the world." He was being literal. Longer levers = more force applied on the opposite side of the fulcrum.
  • 3 11
flag KJP1230 (Oct 15, 2022 at 12:15) (Below Threshold)
 One final intuitive example.

Imagine you are going to be hit by someone wielding a baseball bat. Would you like to be hit by a normal sized baseball bat, or a 6 inch baseball bat? 6 inches is the correct answer (assuming you value your health). The reason is because the force realized at the end of the bat is GREATER if the bat itself (the lever) is longer.

This is also why golf drivers are longer than irons are longer than putters. More force in the longer lever, more control in the shorter lever. Smile
  • 12 1
 @KJP1230: you're thinking of the fulcrum in the incorrect location. You're not wrong about levers, just applying it incorrectly to the bike. If you draw a force diagram you will see.
  • 3 3
 @KJP1230: The baseball bat comparison is a bit off here, as the deal with that bat is that once the longer bat is up to speed, there is more energy in there. To have that amount of energy in the short bat, it needs a lot of speed and you've reached the victim before you're up to speed.

As for the wheel balance thing here, I think there should be a poll. I vote for: shorter chainstay wrt the wheelbase, more weight over the rear wheel. On my previous hardtail, I had a 420mm chainstay and a relatively short wheelbase. Not sure what it was, but I think horizontal top tube was 375mm or so and head tube angle must have been 69deg. This was a DMR Switchback, which has their Trailstar geometry. Especially once I moved my feet from ball of the foot over the pedal axle to midfoot over the axle (effectively stretching the rear center even more) the rear end was completely out of control. It was near impossible to keep the rear from drifting. Which was fun in a way, but hard to maintain speed. And I had some bad crashes because of this. So on my next frame I consciously went with a shorter chainstay and longer front center (415mm chainstay, 460mm reach, 1213mm wheelbase, 63deg HA). Both bikes have five inch travel forks and 26" wheels, so no changes there. Now it is nicely balanced. I can shift my weight rearwards to the point that I get understeer and I can shift my weight forwards to get oversteer.
  • 12 0
 @KJP1230: your level of conviction while being totally wrong is impressive. Lol
  • 1 0
 @misteraustin: agree with this. Perhaps testing something where they can be swapped out with different sizing like a Norco Sight (not sure if the booting connections to the frame are size specific).
  • 2 0
 Thought some of you might find this interesting. I wanted to see how it would affect the geo if we arbitrarily picked a "golden" rear bias ratio and used it to determine rear center length based on the current front center length. Because it is one of the most popular bikes I chose to use the current model Enduro and chose a Rear bias value of 0.65 because it is pretty close to the middle of the current range and right between the current values for a S3 and S4. Keeping this ratio constant you get the following new rear center (chainstay) lengths. Note: currently all sizes are 442mm.
S2: 417mm (likely not possible)
S3: 433mm
S4: 448mm
S5: 463mm
  • 1 0
 @notsosikmik: 417 could be possible. The BTR Pinner for 26" wheels has, according to their geometry chart, 416.88mm chainstays. Right down to the hundredth of a mm indeed, still 0.12mm shorter than 417mm Smile . This is a full suspension bike (but still with an uninterrupted and straight seattube). A hardtail can obviously be shorter.
  • 1 0
 @KJP1230: the lever example isn't relevant here as there is no fulcrum and so no lever in this system (let's say the bike is a HT for simplicity). If there was a fulcrum between the BB and the wheel, as your weight is pushing the BB down, the wheel would be lifted up, not forced into ground. Instead of a lever, the downward force of your weight is just shared between the 2 wheels. The closer the back wheel is to the BB, compared to the how close the front is, the higher the percent of the force it gets. Surely it's clear that a rear wheel positioned at the BB, ie zero CS length, would get the most force?
  • 1 9
flag Twenty6ers4life (Oct 16, 2022 at 13:32) (Below Threshold)
 No, it makes sense and the author is correct. Look at hill climbing motorcycle races, the motorcycles have a super long swingarm, (equivalent of a bike with long chainstays). They’re longer than stock so they have more traction on the super steep hill climbs that they do. On steep climbs with a stock swingarm, (or short chainstays) your weight goes further back beyond the length of the short swingarm/chainstays causing you to loop out on the motorcycle, (or wheelie on a bike) loosing control and traction. A long rear with a long front is more balanced, stable and more traction. It also allows for a more centered riding position which allows for more maneuverability with for or aft body english than a bike with a unbalanced short/long front/rear.
  • 4 0
 @Twenty6ers4life: As you noticed, longer chainstay/swingarm will make it harder to tip over, because your center of weight is further away from the rear wheel, hovewer, this also causes less weight on the rear axle. Therefore for hill climbing you can't have indefinetely long swingarm, cause what you win with more stability you may lose due to less traction.
  • 1 1
 @Twenty6ers4life: But isn't the reason you have more traction with a longer swingarm because the longer swingarm is applying more leverage/weight at the rear tire? Traction doesn't come out of thin air? It comes from weight being applied to the rear tire. (get a truck on mud or ice, it slips unless you fill the bed with weight, then traction...)

My views on this will always be skewed because I'm a long time mountain biker who is big and tall and I only feel like they actually started designing bikes for taller riders in the last dozen years with steeper STA, longer TT's and longer rear swingarms...
  • 1 0
 @stiingya: no, imagine a seesaw. If you sit near the middle and the other person sits at the end, their side goes down, you don't have the leverage. This is a what happens with a long chainstay. Less weight/grip in the rear, unless you are pumping and moving your body because your feet are closer to the middle of the seesaw instead of the end
  • 4 2
 @Dogl0rd: Do you think he understands this one? For the seesaw you have to flip it around. The people are the ground, the pivot is the center of mass of the rider. The confusing thing with your model is not only that it is upside down, but also that both people have the same weight. And you end up with a dynamic situation (the seesaw accelerates) whereas the balance issue here was a static one. Yes it could be used as an example, but considering we're this deep into this discussion (which is amusing in its own right) there may be too many differences for it to be used as a good example.

I'll try another one. Carry a beam with two people and put one person (considerably heavier than the beam) on top. If the person is in the middle, both carriers experience the same load. If the person walks all the way to the rearwards person, that person will have to lift more weight. If the person walks beyond the rearwards carrier, the front carrier will eventually have to pull down to keep the beam horizontal (and the rearwards carrier will have to carry everything plus what the front person pulls down).

That kinda brings us to the situation of looping out. Of a (motor)bike on an uphill slope, in the horizontal projection the center of mass shifts closer to the rear tire contact patch. This is because in this center of mass is above the wheels hence when the bike tilts backwards, the center of mass moves backwards too. Not just that. The tire contact patches more ahead of the wheel axles in this horizontal projection. So yeah indeed, you'll get more traction over the rear tire contact patch when climbing and at some point you may even go beyond this patch. This causes you to loop out as unlike in the example of the beam, the front carrier (your front tire) can't pull down. In the dynamic situation (you try to accelerate up that hill) you could even loop out even if your center of mass isn't behind the rear tire contact patch (in this horizontal projection again) but I won't dare to discuss dynamics at this point as I can't make drawings in this comment section. But yeah, if this is a concern (looping out, not the lack of traction), people may opt for a longer rear center.

TL;DR: Don't shoot the messenger.
  • 2 1
 @KJP1230: I 100% guarantee you I am correct. I doubt I would have made it through Physics 1&2, Engineering Statics, Dynamics, Linear/Differential equations, etc. and 4 years in Mechanical Engineering Design if I didn't understand VERY basic load lever situations. Spend a minute actually considering the model I presented regarding a super long chain stay. Hopefully you have the willingness to learn something new and understand a bit more about physics and the dynamics of your bike. Your elementary science teacher sounds like an awesome guy for picking up his car, but unfortunately it seems the full concept didn't quite sink in for you, as you are thinking about the lever arm situation backwards still. Spend some time on this one, and don't be afraid to learn something new. Don't be too big to be corrected, and you will never stop growing, learning, and understanding the world better.
  • 1 0
 @misteraustin: This has been an epic debate.
  • 1 1
 @vinay: TLDR indeed
  • 2 0
 @jesse-effing-edwards: This whole article and all the comments following was just frustrating... It would be nice to see PB revisit this with some more thoughtful and valuable info/data, and actual ways that cs length affects bike handling.
  • 1 0
 @misteraustin: it would be nice if the media was the authority, ha
  • 2 0
 @Dogl0rd: I don't see how the seesaw fits fits in? The person standing on the end of the "lever=seesaw" is applying HUGE amounts of leverage on that end... That's why it's going down!! Smile

But I think this is the heart of the matter for me. It's climbing that longer rear ends have been a nite and day difference to me. undulating and DH I can still ride fine with a "longer" rear end. So win/win...
  • 2 0
 @stiingya: lol we're on the same page. I know a bike isn't a seesaw, but a seesaw is a moment arm that most people understand
  • 3 0
 I agree the article has it all bass ackwards. And this discussion - a bunch of chickens running around squawking. What i find interesting is that folks here know how to ride but the justification words are all confused.
  • 2 0
 @captaingrumpy: username?
  • 191 11
 is it time to just go and ride your bike?
  • 90 3
 Only if you have a BMX background
  • 20 41
flag 8a71b4 (Oct 14, 2022 at 9:31) (Below Threshold)
 If that was the mentality, we would still be on 26 inch bikes with 69 degree head angles and 100mm stems.
  • 16 1
 I think what people really need to do is to decide if a bike is good or not based on a spec sheet
  • 54 0
 I think "run what you brung" approach is totally appropriate for riders and consumers. You don't need to be thinking about minor changes to your gear all the time. However, it is not an appropriate approach for companies who are selling us really expensive bikes and making big claims about their performance without properly addressing fundamental issues like "does it fit". Companies need to be held to account by the media, or else we'll just get products dictated by marketing slogans all the time.
  • 7 0
 @8a71b4: that’s me!
  • 3 0
 @8a71b4: some people are lol
  • 2 0
 @8a71b4: reduce that stem length and you have yourself a dirt jumper. so I'll take it
  • 11 0
 @8a71b4: what good is a "better bike" if we're still neurotic to a fault about it? The best bike is the one you (choose to) have fun on.
  • 3 0
 Not if it has crank arms longer than 170mm.
  • 4 0
 @8a71b4: dude, that’s my favourite kind of bike, it has the shortest chain stays possible.
  • 2 0
 @peterman1234: the best bike is your next bike due to the N+1 law of bike nature
  • 4 0
 @panaphonic: I think we need to all put our heads together and figure out the ideal seatstay length first, and perhaps a breakout session on cable housing.
  • 144 0
 "Maybe this oversteer is what people mean by “playful” chainstays?"

I think most people think of shorter chainstays as being more playful because shorter chainstays typically make manuals and bunnyhops easier. The front end is typically easier to lift, so for most that equates to being able to play around a bit more on the trail.

Having had a quick play on bikes with longer stays, they definitely feel like more work to manual or pop over little kickers and jumps. I know someone who switched to a high pivot bike with a decent amount of rear centre growth through the travel, and they ended up getting rid of it because further into the travel as the rear centre extended it made popping the front up on awkward/techy lines harder than they liked.
  • 16 0
 Exactly my thoughts
  • 63 1
 Amen. After 32 years of riding, and of all the 25 or so mountain bikes I’ve owned in my life, my favorite bike for bouncing around is my current 2018 Process 153 with 425mm chainstays. It’s the bmx’ers mountain bike. It’s like that classic Cindy Lauper song “Short Chainstays Just Wanna Have Fun”. That was an excellent joke.
  • 32 0
 Different backs for different tracks? On my old trails which were tight & twisty but kinda flat, I loved a short chainstay bike for the poppability and 'playfulness' even when the reach was a bit longer. But now I climb slow & steady for an hour and then lump down more natural terrain and stability feels far more important, so now I appreciate longer stays than I would have liked in the past. The idea of 'balance' seems a bit subjective as everyone is built different and positions themselves different out of the saddle, so not sure I buy the idea of some perfect ratio, but I can definitely appreciate that different styles of riding will benefit from a different take on chainstay length (wheelsize also being a factor).

We're all the rider we feel we are inside.
  • 3 0
 Exaaaactly
  • 6 1
 Yup a friend of mine blames high pivot rear.growth for a bad crash on rock drop due to its behavior. X dh racer
  • 6 0
 @jrocksdh: This is a background nightmare for me. Approaching a roll that turns out to be a drop and having to pull up at the last second.
But I do think longer stays would suite most riders that prefer to plow than play.
  • 4 0
 @chubby5000: same here, will not let go of that bike. Keeping it alive with parts every chance I get
  • 1 1
 Last bike I got back in 2018 I drank the kool aid and deliberately went short travel (130) and short chainstays (425) for exactly this reason. I love that bike, and I have learnt to bunny hop and just about manual on it , but I've got no idea if my thinking the short chainstays helps is just placebo effect? @mattwragg I know a rider of decent skill can manual any bike, but any opinions on whether it is actually easier on shorter chainstays?
  • 2 0
 @chubby5000:

Curious, what size Process are you on, and how tall are you?

I had that exact bike (the 29'er variant), but eventually sold it because of what felt to me like "too short for me" chainstays.

Funny enough, the latest revision of the Process 153 has 435mm chainstays (and a slacker 64.5 degree HTA, vs the original G2's 66 degree HTA). So I wonder if they were trying to keep some balance/ratio there with the update vs the original design.
  • 1 0
 @ocnlogan: the new one sounds even better on double blacks and steeper trails. The 425mm CS def has an affect at hight speeds and in steeps, even if it's fun elsewhere, always a tradeoff..
  • 1 0
 @chubby5000: I used to have a Process 111, is one of my favorite all time bikes.
  • 3 0
 The Spec Status is awesome too @chubby5000:
  • 4 0
 My bike has a 415mm rear center with a 1213mm wheelbase. Feels fine for me.
  • 24 4
 Shorter chainstays are a huge boon if you want to quickly lift the front end. Come round a corner at speed and see a 1' tree down across the trail and with shorter chainstays you've got more chance of hopping it cleanly rather than just having to slam the anchors on and slide into it. Similarly for changing direction off a straight line.
But the thing is, if you want long chainstays you are spoiled for f*cking choice, if you want short chainstays you are increasingly shit out of luck. 435 is now considered short FFS.
There is a reason that every discipline of riding that needs manouverability and "playfullness" goes for the shortest chainstays they can manage. BMX, DJ, Trials etc.
Sure, if you just want to plonk yourself down on the seat of the bike and aim it straight up or down a hill then long chainstays are probably ideal, but there are a lot of us that want to have some actual FUN!
  • 7 0
 @G-Sport: Exactly everyone is actin like this is a blanket statement. For those who want to plow in straight lines or want to make up for lack of skill with a ridiculously long bike that's totally fine. AS LONG AS there are options for people who want playful or flickable bikes. As a freerider I really like shore chainstays and a pretty short reach. There isn't an advantage to longer chainstays in such a scenario. What needs to happen is that everyone has choices, not all the chainstays should be long and not all of them sort. A ong as I can get some short 430 or less chainstays all is good.
  • 6 0
 @NoahJ: look at specialized status, think chainstay length is around 426, then choose your reach.
  • 2 0
 @Woody25: i ride a 2016 yeti sb6 with 404 reach/442 chainstays, i used to be decent at wheelies, bunnyhops etc, but it takes a lot of effort to move mine around. Im 5,7.
  • 3 0
 @ocnlogan: I'm 5'11", 174lbs nekkid, place in the 30th to 40th percentile in the local races (all ages) and I'm running a solid 5" of self esteem. I'm on a large and people say I'm like an Italian Flamenco dancer on my bike (nobody has ever said that).
  • 7 1
 @NoahJ and @G-sport

totally agree. Not a pro but I can hop and manual my Remedy no problem and its great fun. It takes a fair bit more effort but I can get the front wheel up on my Session (27.5" wheel) at will and with confidence. I recently got a custom-geo HT. 29r, shortest CS I can go with my current wheel is 445mm, 315mm BB/60mm drop and I can barely lift the front wheel over a curb and even that takes a herculean effort. Its stable and corners very well but overall I'm somewhat disappointed with the thing.

G-spot's comment about plonking down on the seat and aiming it straight down a hill is, I suspect, is largely what we get from bike reviewers.
  • 2 0
 @Crankhed: Yeah my buddy has one and he loves it, and I rode it around and couldn't believe how easily the long front end got off the ground. Someone was telling me about a demo day in Squamish a while back and one of the guys running it chose a Status as his personal bike for these reasons.
  • 3 0
 @freerabbit: yeah, finally, the coherent bit of the article.
  • 1 0
 I've got two bikes with similar geometry except one has shorter chainstays. The longer stays definitely make manuals a bit harder, but for playing off side hits and popping off kickers how progressive the suspension is seems far more important than the chainstay length. My long chainstay bike with super progressive suspension has way more pop than the shorter more linear bike.
  • 1 0
 This is the thruth 335mm cs playful flip chip 345mm for hauling but bike was less fun ... length doesnt matter Smile
  • 2 0
 @G-Sport: glad to see George French himself chime in. Any chance of seeing some mtb products in the future?
  • 2 0
 Exactly what I mean by "playful" comparing my Canfield Lithium (430mm) to my Banshee Titan (452mm). Lithium manuals and bunny hops when you think about it, Titan does it when you WORK for it. Cornering characteristics are definitely different and I have to warm up to each in a similar way to carving on skis with different sidecut radii.
  • 2 0
 @Woody25: It changes the dynamic for sure - so long as you have a decent amount of strength it's a slightly different technique/timing to hop or pop a longer bike, but if you have the setup right, I personally feel it's just different, not particularly better or worse.
  • 3 0
 @panthermodern: Thanks dude. Yes. Been working on a few things for literally years but it's slow going, hoping to have something significant out next year maybe.
  • 2 0
 @COmoose: Exactly. With short stays it happens much quicker, with long ones I need a second or more to pre-load the front and build up momentum backwards. It's obvious on pulling up but the same thing applies to changes of direction laterally. Sometimes, you just don't have the time for this, but also most of the time I can't be arsed with this.
  • 74 0
 Why would a shorter chainstay equal less weight on the rear axle? My head is just seeing this as the reverse. Perhaps that's why I dropped out of engineering 15 years ago.
  • 38 1
 Maybe you should have stuck with it. You’re right shorter chainstays do increase weight on the rear wheel, if you keep everything else the same. It’s possible that the bikes the writer was riding did not keep everything else the same, but if the weight on the rear wheel truly decreased, what he needed was even short chainstays relative to the rest of the bike (which I highly doubt is actually the case).
  • 15 1
 As a recent engineering graduate I had to grab another cup of coffee reading this. You are right though, it’s more weight on the rear. I have 521mm reach with 440mm CS and I feel like I have oodles of grip in the rear, much to the demise of my rear wheel
  • 18 0
 I stopped reading the article after that sentence. Shorter chainstays obviously shift the center of mass rearward, assuming the same body position.
  • 6 0
 @bikeracer28: I interpreted this as when the shorter chain stay is present, he ends up hanging off the back and unweighting the front wheel, so to get good steering he leans forward. Where as with a long CS he can be more “centered” in the bike where he doesn’t have to shift backwards to “feel” like the rear axle is weighted. If not so much the physical force but the feeling of body position due to bike fit.
  • 3 0
 this does seem reversed? short cs to long fc ratio tends to result in rear weight bias & front push (requiring actively having to weight the front to get things to hook, rather than driving from a stable centered position).

but i agree on his statement that balance is crucial - having tried several bikes with similar reaches (490-495), and chainstays ranging from 420-445; the longer rc bikes were the best cornering / dynamic handling (best at fast directional transitions, etc).
  • 6 0
 Yeah, I stopped reading after that. Matt does not know what he's talking about.
  • 44 10
 What makes people continue to think that “balance” means chain stay and reach should be equal? They are not equivalent measurements—- reach doesn’t measure to either wheel axle. It’s like if I want my car to measure the same dimension from gas pedal to rear wheel and gas pedal to front bumper.

And how is it physically possible that hopping on a shorter chain stay bike “manifested itself as less weight on the rear wheel”?

**Disclaimer— long-standing short CS advocate here, though presently less dogmatic than I used to be.
  • 6 0
 Yeah, that paragraph left me very confused. As well, any serious discussion needs to also add in front center (rather than HTA) and saddle position, which is nearly impossible to clearly lay out thanks to the hijinks of modern seattubes.
  • 3 0
 I am not sure anyone is saying CS and Reach should be equal in order to achieve a balanced bike. I believe Matt mentioned 460mm reach and 440mm CS being a proportion he likes. Having the same Reach/Chain stay proportion across sizes obviously makes a ton of sense, otherwise they are more or less different handling bikes between sizes.
  • 5 1
 I was confused by that comment too. A shorter rear center means that rear wheel is further under you putting more weight on it. I have an argument for shorter chainstays on downhill bikes as compared to Enduro, trail, and xc. If you want your front and rear center to be similar lengths and therefore balanced, I would argue that you should take this measurement from your center of mass straight down with gravity when you're in the attack riding position. If you're on a 10% slope, then that line would be slightly more forward than if you were on flat ground resulting in wanting shorter chainstays and longer reach to keep that balanced positioning on the bike. If you were on a 20% slope, that line from your center of mass would be even farther forward meaning longer reach still and shorter chainstays to stay balanced. If you don't want to keep extending the reach, you could also slacken the HA because the distances you're measuring is from a line straight down from your center of mass following gravity, then a measurement from that line to your axles. To have the best balance, those should be equal at the steepness of terrain you're riding.
  • 2 0
 Reach in this case is a somewhat odd metric to use because it takes away HTA and fork length, both of which can dramatically alter the length of a bike (and thus how easy/difficult it is to weight the front wheel). To me a proper "balance" (if you're looking for it) is a front center to rear center ratio. Personally I've found a front to rear ratio of about 1.78-ish to be a pretty balanced bike, but YMMV.
  • 1 0
 @vitaflo: yeah you're right. It's more of a front center to rear center than reach. Lots of measurements go into front center.
  • 2 0
 @loganbeck: totally agree! These are the things that you can't determine just from measurements on a page of a bike's static geometry. Surely a lot depends on the user - their body type, riding style and position, terrain and usage. There's no holy grail of geometry ffs. I understand that we all want to tinker and strive for the ideal machine, but a lot of this discussion seems to be about buying into the idea that we all need new bikes all the time. How you ride is so much more important than a millimetre here or there on your bike and improving yourself, whether it be confidence, physicality, mentality, etc. makes for way bigger gains imo. As does improving your local trails.
  • 31 0
 "I’m 1.75m/5’9” – an average-sized human, more or less. Last summer I was on a 29er with 465mm reach, 64-degree head angle, and 435mm chainstays. Coming off a few years of almost exclusively running longer-chainstayed bikes, the first thing I noticed was the weight distribution. Initially, it manifested as less weight on the rear axle, so less traction."

Can you explain how shorter chainstays result in LESS weight on the rear axle? This doesn't make any sense to me. The closer your center of mass is applied to an axle (the closer your bottom bracket is to the front or rear) the more weight, and therefore traction will be applied.

The reason people like longer CS bikes is because it applies more weight to the front wheel via the feet.
  • 4 4
 It’s not less with long chainstays, it’s more, however you may have to relearn weight distribution.

Consider how weight distribution affects climbing, too much weight back and the front end gets light, too much weight forward at the rear end gets light; simple physics.

A longer RC increases stability, but does not increase traction, weight transfer is what creates traction.
  • 12 0
 @sanchofula: Yeah this is a basic physics situation and Matt is wrong in his statement. The longer your CS is relative your front center the less weight will be put on the rear wheel. Basic physics. Would love to hear from matt about what his reasoning is.
  • 3 2
 @plustiresaintdead: pretty funny how you got +10 upvotes and I got downvoted Wink

Still, physics don’t lie, but people gonna be what people gonna be …
  • 1 0
 @sanchofula:
Yeah kinda unfair I suspect people aren’t quite understanding what you’re saying but I think you’re closest to interpreting what Matt is sensing but not saying: he is compensating for the short CS by putting his weight forward on the bike (which is what you need to do cos there’s less weight on the front wheel), but that he’s finding this compromises his riding style relative to a more balanced bike.

It’s the physics of the compromise which is less obvious, but it seems reasonable to think that a bike which demands you to lean further forward in corners may not corner so well. To postulate, perhaps the problem relates more to consistency of grip generated because of the relatively more limited mobility of having to commit more weight forward and to an extent through your arms (think being on the drops on a road bike as an extreme example), rather than being more centred, driving weight through the BB and being able to make small adjustments more easily.

Anyway, this article all feels like a bit 2020. Chainstays are getting longer. More bikes are coming with size specific CS. This is old news
  • 29 0
 Damn it's almost like both short and long chainstays have a place in mountain biking. Short CS for yanking off every little roller and long CS for plowing through stuff. Make CS flip chips more common so I can change em up based on my mood.
  • 5 0
 Agreed. It is almost like different people have different riding styles and reasons for riding. Personally I am not racing. Just riding for fun and fitness. I find short chainstay bikes more fun (granted other geo things also play into this massively) even being 6'2" so I prefer them.
  • 3 1
 Seconded.

I like bikes with longer stays, because they feel more 'jibby' (since many get persnickety about the use of the terms 'lively' or 'poppy', perhaps this works better). I've always liked Evil bikes because they definitely have this ride feel. Shorter stays contribute to that feel.

I also like longer and more stable bikes. They feel more stable and composed, and tend to corner and carry speed better.

The one thing I think we need to get away from is the notion that any specific geometry is inherently better.
  • 1 0
 +1!!!
  • 1 0
 My exact thought More flip chips in more places is just, more better and reach adj. HS cups
  • 2 0
 @jerrytek: im very confused. Short stays definitely feel more jibby. And evil is known for their short stays not long ones.
  • 2 0
 @NoahJ: My point was that I can appreciate bikes with different geometry and different ride feel. I find that Evil bikes are at one end of the continuum. But I also like more stable bikes as well.
  • 2 0
 @NoahJ: he mistyped
  • 1 0
 Agreed as well. It's what so frustrating about companies using travel as the main differentiator between bikes. Everything is trending winch and plummet geo regardless of travel.
  • 1 0
 And reach adjustments like Guerrilla Gravity does!
  • 1 0
 Speaking of "short" or "long" chainstays in isolation means nothing. Any chainstay size can be said to be short or long, too short or too long, depending on the front center size and rider preference.
  • 19 0
 Interesting read. I agree with what you are saying about longer chain stay bikes having a lot of desirable handling characteristics, but I believe your logic is off a bit.

"Initially, it manifested as less weight on the rear axle, so less traction"

Shorter Chain stay bikes put MORE weight on the rear tire, not less, like you mentioned. This is a pretty simple math equation, lever/load situation. That's not to say what you are feeling is wrong, but your explanation of it doesn't really add up. I believe what you are feeling is that a shorter chain stay bike has more grip on the back tire and thus less on the front. In order to get the front to grip, you need to lean forward more, and thus, you are all out of balance and when the rear DOES lose traction, it is FAR less predictable of a slide than a long CS bike. It "Snap" oversteers quicker.

I too find long CS bikes a lot more fun and playful bc they let you goof around so much more within the bounds of grip. But I believe that is because the edge of traction is far more predictable than an imbalanced short CS bike. There is no "right or wrong" but a 490mm reach bike with a 425mm CS length is certainly an imbalanced bike. whether that is fun or not is subjective.
  • 8 0
 yeah you're correct on this. I commented the same thing. Matt's analysis is based on a totally incorrect assumption.
  • 21 6
 Banshee seems to be the only company that has it figured out. Most of you are on a bike with reach that's too long and chainstays that are too short. There's a reason all the top enduro racers are on bikes that Pinkbike would call too small.
  • 2 0
 My Runes v3 ( and V2 previously) are the only bike I had on which I don’t have to think about my weight distribution
  • 5 6
 Yes, it’s because they ride trails they don’t know very well (if at all) and need the extra manouveruability.
  • 4 0
 this, Bikes like the stumpy evo are well balanced in their geo and setup you dont need to be swinging off the back or over the front to get it to actually grip.
  • 3 2
 @Trailsoup: yes and no, many of those riders also always ride those bikes anyway and proves unless you go to the bikepark... a shorter bike is better.
  • 2 0
 @Trailsoup: Yes and no. One of the EWS Remy's tested this out in his local BC trails (which he knows very well). He was swapping reach adjust headsets etc etc. He's like 5-10 and sized down to a medium because it was just better for him. I think he's at 455mm of reach on an enduro bike. I think guys that are riding SMALL bikes like Jack Mior certainly will go to a proper fitting bike on their local trails...but they aren't like upsizing like Matt Wragg basically has done (sort of).
  • 7 0
 I went from a Bird (long reach, short stays) that I really enjoyed riding (although you needed to be confident and over the front to get the best of it) to a Titan and the Banshee is just so much easier to ride. If I was feeling crap and lacking a bit of confidence the bird was really hard to ride properly because you had to be so concsious to get weight on the front, but the titan is just..easy. If I'm having a crap day and not feeling it, it's easy and predictable and gives me more confidence.

I'm sure there's a ton of stuff that we're not fully considering about biomechanics like flexiiblity and strength and leg vs torso vs arm length, without even getting in to your riding background, but for a bum average rider like me it''s more predictable, friendlier and more fun to ride than most other bikes I've owned.
  • 2 0
 "Most of you are on a bike with reach that's too long and chainstays that are too short."

This is operating on the assumption that everyone wants similar bikes, and any deviation from that is an error. There is (and should be) significant space for personal preference. If that works for you, great. But its also fine for different people to like different bikes.
  • 1 0
 Im on a Forbidden Dreadnought and its perfecly balanced.
I think threre is no other Bike Company out there that delivers the same Frontcenter/Rearcenter ratio between al sizes appart from Forbidden.

And ive been to the Tropy of Nations Race lately, never seen so many Forbidden Bikes. Racers seem to like the Idea of a balanced Bike aswell, atleast some of them.
  • 1 0
 @JustMaffin: I am on the fence regarding Drednought's RC, especially at sag (XL should be around 480mm), but Druid seem to be spot on. Unfortunately, don't have any experience with either.
I do agree with you though that Forbidden is, not the only, but certainly a rear company that is doing the balancing right, with many other companies now touting proportonal chainstays on their new models, while in reality they are just offering a couple of milimeters increase in RC for additional centimeters in reach. Hardly keeping a balance.
  • 2 0
 Have a Titan I love but only sort of agree. Picking out a bike, I look at wheelbase, FC vs RC, and HTA in the context of what I'm going to use the bike for. Then I look at reach, stack, STA and do some math to figure out if I can get the positions I want without being right at the end of the saddle rails or going longer than 50mm on the stem.
  • 13 0
 Can we talk about background here for a second? I think that really does play into things. Hear me out.

TLDR: People who grew up with BMX, or other small bikes might prefer shorter chainstays and the playful/poppier riding style. Whereas people who grew up on dirt bikes or other larger things, may prefer longer.

A buddy and I both like riding. He is 2-3inches taller than me, but was VERY good at BMX/Street riding as a kid (qualified for the X games at age 15). I grew up trail riding dirt bikes (Honda XR's).

Bikes that my buddy describes as being a "plow" feel "twitchy" to me. Bikes that feel normal to me, he describes as an "ocean liner".

Turns out, he rode countless hours more on bikes with near vertical HTA's, and tiny wheelbases (and has the skills to back it up), while I grew up riding dirt bikes with 62 degree HTA's, and 1400mm plus wheelbases. So that colors our perception of what the bike should behave like.
  • 5 0
 As someone with a BMX background I can vouch for your hypothesis about background heavily weighing in on this argument. My current bike I feel has too long of a CS, but options are few and far between these days. Frown
  • 3 0
 I like this take. I started riding when NORBA was king; gravel bikes would be embarrassed to be seen with geo that steep. Everything feels super stable to me now, XC or enduro. On the other hand, my son's never ridden anything steeper than a 65 degree head angle.
  • 4 0
 @ohbmxer: aren't there still a good number of brands with short CS? Evil stands out in my mind on this. Canfield too. At a minimum, there are still loads of brands with one CS across all sizes...
  • 3 0
 @shredddr:

Offhand I think its still fairly split between "short" and "long", although "truly short" may be getting rarer these days. And I do think the average is starting to move up, especially on size L and XL frames.

Here are some random ones I can think of for those wanting "short" to "quite short" 29'er chainstays.

Commencals Meta TR (435mm)
Commencal Meta AM (433mm)

Canfield Tilt (425mm)
Canfield Lithium (430mm)

Specialized Status 140/160 (both with 426mm)

Kona Process 134 (426mm)
Kona Process 153 (435mm)
Kona Process X (435mm in the short position)
  • 3 0
 @ocnlogan:

Totally— plenty commenting here on how longer CS generally feels more balanced, and “corners” better. I wouldn’t know. On my favorite trails here in the Northeast, and the ones I learned on, not sure I’ve ever “carved a corner”— every change of direction is mid-rock, root, step-up, log-over, off camber, rock ramp, mid-stream, or something else. Check Debacle at Blue MT. Map looks like a bowl of spaghetti but damned if you’d find a corner anywhere on that trail. I learned to ride in a style where you’re lofting the front wheel, or floating the rear, or some other body English to make virtually every turn. Part of my penchant for shorter CS.
  • 12 0
 While we are at it, how about we put a little more emphasis on overall effective top tube length, you know, the measurement that dictates how much your lower back does or does not want to explode when you're seated climbing (75% of the time of a bike ride).
  • 14 1
 I'm only seated in the chairlift.
  • 1 0
 You need to balance ETT and reach to really figure that out. When ESTA goes up, ETT (in particular the amount of top tube behind the BB) goes down so we've increased reach to compensate.
  • 2 0
 I think of riding as what happens when weight not on saddle and pedaling is what happens when weight is on saddle. Except for mile munchers, geo should be as optimized for riding as much possible without compromising pedaling positio.too much. Usually pedaling position can be solved with saddle fore-aft, stems, and bar rise. ETT of secondary importance and basically the same thing as STA. I want reach optimized for riding.
  • 15 1
 You know, I misread the title to "Its Time to Recalibrate Our Ideas about Chastity Length."
  • 11 0
 I gave up chastity when I divorced.
  • 11 0
 People never talk about bottom bracket drop as an important component to 'playfulness'. I think it's possibly more of a factor than chain stay length when pulling back for a manual or bunnyhop
  • 2 0
 You say this, but then say nothing about how you think bottom bracket drop affects 'playfulness'!

What do you think is the ideal BB drop vs wheel size vs rear centre vs etc.?
  • 1 0
 @boozed: HOW did you do italics! Also interested in knowing how BB drop affects playfulness
  • 1 0
 @Dogl0rd: Most of the PB forum's formatting codes work here too
  • 10 0
 This is an interesting topic but a completely incoherent article.

If the point is that chainstay length should generally scale with reach to allow a weight distribution balance, then just say so up front (and for the record I agree).

Really, though, the underlying issue is that for 99% of us (me too) there's not an *objective* ideal. There's just a subjective one, where we feel the speed/flow/whatever and just have a blast.

-W
  • 9 0
 As you've said, suspension setup/platform plays a big role in this and also Long Stays, especially alloy flex alot.

Im a firm believer in fully adjustable bikes, why cant i have a 435 or so CS for my locals and then adjust to 450 for the park etc? does this compromise sales?
  • 3 0
 I've been curious about this for a while. If you don't change the linkage in any way, but make the chainstays 15mm longer you would change the leverage rate of the suspension and should have a little more travel - right? Would it be much of a change in travel?
  • 1 0
 @czyk123: You're correct. It should change a whole mess of stuff. I don't know how drastically though, or if it would manifest as a big enough change to be noticeable to the operator.
  • 3 1
 @czyk123: Yes, Wheel leverage plays a huge part - the rocky above is a good example, If you found a good suspension setup but then change to long setting the bike suddenly feels like your running 40% sag instead of the 25% before hand.(those are a bit dramatic but you can definitely tell its not feeling the same

Theres many that disagree which is fine, They just dont understand how suspension works lol
  • 1 0
 For single pivot or VPP-style back ends, it wouldn't be especially hard to make swappable back ends, or even big old flip chips on both sides (obvs including axle, brake mount and mech hanger). Harder on Horst, as the axle is on the seat stay. Would add weight, but only change leverage ratio and travel by, say 3%.
  • 5 0
 @HeatedRotor: 15 mm isn't going to change your sag to 40% from 25%, "a bit dramatic" for sure.
  • 3 2
 @Joecx: "feels" being the keyword here. Dont take snippets of context.
  • 2 5
 @HeatedRotor:

"Theres many that disagree which is fine, They just dont understand how suspension works lol"

If you're going to school us all about it maybe try a bit less hyperbole and stick to the facts.

BTW, there is a spell check on here.
  • 1 1
 @Joecx: Cool - just remember its only a internet forum, Don't get to wound up there mate.
  • 2 0
 @czyk123: Depends on the suspension design, but on a simple signal pivot, a 150mm bike with a 430mm chainstay would become a 157mm bike if the chainstay was extended to 445mm, all else being equal.
  • 1 0
 Guerilla Gravity does this with swappable seat stay kits. Trail Pistol (430mm CS), Smash (440mm CS) or a Gnarvana (450mm CS). Also, the bikes have adjustable reach with rotating cups. It's like the Swiss army knife of bikes.
  • 8 0
 Somebody explain this to me (quote from the article below). I must be missing something because this seems counterintuitive. Wouldn’t shorter chainstays out the rear wheel closer, thereby exerting more weight into the axle? Or is it better to think of this like a lever where your body weight and force can more easily whip the rear end around if the lever is shorter?

“Coming off a few years of almost exclusively running longer-chainstayed bikes, the first thing I noticed was the weight distribution. Initially, it manifested as less weight on the rear axle“
  • 8 0
 You are correct. Matt is wrong.
  • 2 0
 My impressions would be:
"Coming off many years of exclusively running shorter-chainstayed bikes, the first thing I noticed with the longer chainstays was the weight distribution. Initially, it manifested as less weight on the rear axle, and consequentially less traction"
And while impressions are a personal thing, these impressions in particular, unlike Matt's, are backed by facts. It's undeniable that the shorter the chainstay, the more weight is concentrated on the rear axle.
  • 7 1
 Loooove this article. I’ve been saying this for years. That particularly on large and XL size frames, chainstays should be larger than they are for most bikes.

Ironically, I’m a newer rider to the sport, so I didn’t really have a dogma to start with. I started riding late in 2018, and my first bike was a G2 Kona Process 153 29’er with 425mm chainstays. And I found I had to keep removing stem spacers and go to shorter rise bars to keep weight on the front tire, so I started exploring other bikes. At 6’1”, I’m now on a Banshee Titan, with 452mm chainstays, and I’m considering trying the longer ones.

My favorite way of comparing bikes weight distribution is finding their front center/rear center ratio. This accounts for reach, head tube angle, and travel. It’s really interesting to see how some bikes are VERY differently weighted than others. The forbidden dreadnought in XL, vs a Canfield Lithium in size XL for instance.

I also am starting to think flat pedal riders may prefer a bit more chainstay length. As you drop your heels for stuff that shifts your weight back, which means a more rearward weight distribution than someone on clipless pedals.
  • 10 1
 Long chainstays make a bike easier to ride, because the bike is more stable, but once your skill set grows, a shorter RC is more playful. The only time I have ever felt like a long chainstay would help with control is gounb Mach chicken in a straight line, and honestly, all I do is hang back a little and it all good
  • 3 0
 It’s the opposite with flat pedal riding, a shorter chainstay is more agile and feels better with the loose foot to pedal contact.

Cleats increase control and allow a rider to manipulate a longer chainstay.
  • 3 0
 @sanchofula:

I'd think a shorter chainstay would be more agile, no matter the pedal type. And agile is another way of saying "less stable", so no argument there. And agree on shorter CS bikes being easier to manual.

Ironically, I don't notice chainstay length at all in a straight line going "mach chicken". For that I'd think that wheelbase would be the main thing you notice.

Personally I notice it entirely in turns, where, I find weighting the front wheel much more intuitive. I'm not having to fight front end washouts really anymore.

Then again, I'm relatively tall (6'1" barefoot), with very long legs (36.5in saddle to pedal height). So even if I stand and hinge at the hips the same way as most folks, my torso being shorter, and legs being longer means my weight is usually farther back.

Stuff like this though is why I love seeing adjustable CS lengths in bikes now (RM Altitude, Kona Process X, Stumpjumper Evo, Raaw Madonna, etc). So both of us can have our cake and eat it too Smile .
  • 4 0
 @ocnlogan: Yeah I think Size Specific chainstays, coupled with a 10mm adjustment of that chainstay would be what I'd want in my next bike. Basically do like what Rocky did with the Altitude but also make the lengths grow by size category (like SM, M start with 434mm-444) and (L-XL be 438-44Cool . You'd get to test and adjust fitment that works best and also adjust for certain trail types. Big flow rider trip with a zillion jumps and ramps...short CS. Natural enduro trip...longer setting. Best of both worlds. I can see Rocky doing this as they are all about adjustability.
  • 2 0
 @sanchofula: I've had the opposite experience. I notice a long CS makes the biggest difference in corners and the better I get at riding the more I like long CS's and want to try even longer ones.

The only thing I really like about short CS's is easy manuals, and exceptionally slow techy steep riding. But, as I get better, I'm riding those steeps faster anyway so the benefit is waning.
  • 1 1
 I almost agree but I do need to point out how you stand on your pedals does not effect how you weight the bike. The force pushes straight down on the bottom bracket always (unless you're pedaling), and the bottom bracket cannot translate moments, its effectively the same as a pinned connection
  • 14 4
 425mm. I will die on this hill.
  • 3 1
 Yup, easier to ride tech, more maneuverable, better traction, pretty much no disadvantage unless you need a plow.
  • 2 1
 @sanchofula: I live in the southwest desert which is pretty much the definition of tech and find short chainstays suck for me especially when climbing...downhill I can deal with it. I'd much rather have a 440+. BUT I think a lot of it has to with my long legs that put me more rearward even with a good STA. But someone who rides with their seat 3" lower is much more centered on the bike and less affected by stubby chainstays. I think the trends of larger bike longer stays is probably about right.
  • 2 0
 Damn right!!! Shorter the more fun.
  • 2 4
 @foggnm: Short stays are awful in tech descending. Long stays ftw. Short stays are good for slashing berms for the gram and thats about it
  • 3 1
 @gabriel-mission9: not if you know how to descend the tech
  • 5 1
 I sold my Banshee Phantom because I hated the long stays. Everything else was great. I will never buy a bike with stays longer than 435 mm and I would prefer shorter.
  • 2 1
 @gabriel-mission9: your and my ideas of what's tech may vary, but for me, that's when I most value the option of a quick/easy manual. I am not usually trying to go fast though, happy just to pick my way down the scarier stuff. I'm running a 26" rear wheel on my 27.5 bike and enjoy how it makes the chainstays feel shorter.
  • 2 0
 @sanchofula: I think this is true, up to a point. Specifically high speed steeps and getting hard on the brakes.
As a taller person on a short bike, I have to get back over the rear tire or I feel like I'm going OTB. Then my weight is back and it's hard to get good front grip going into the turn. Short bikes just take a lot more weight shifting vs a longer, 29er wheel bike where you are more centered in the bike instead of sitting on top of it.
Seems to be why DH bikes have been getting longer in the last 10 years, especially for the tall DH pros.
  • 2 4
 @sanchofula: What's telling is that everyone who says this never mentions cornering. You win races in corners, not by "maneuvering" or with straight line speed through tech. And imbalanced bikes corner like shit.
  • 1 1
 @foggnm: I also live and ride in the southwest, maybe your flow trails work better with a long CS, but tech riding and short CS are the ticket out here.
  • 1 0
 Lol. You lot are mad. Short stays for flow tracks. long stays for real dh. When I go full gas into an extended rock garden, I don't want tiny little stays getting kicked all over the place. long stays for calmness and predictability when all hell is breaking loose around you. Short stays are for pinpoint direction changes when they trail isnt doing much at all
  • 6 0
 Biggest issue I've got with longer CS is how it affects my manual & bunnyhop. High pivot bikes like the dreadnought pictured above really turned me off as I couldn't manual or hop nearly as well (they lengthen quite a bit)
  • 4 2
 Yes, if you just make the bike with longer chainstays, manuals and bunnyhops get harder. 100% agree.

But longer CS's also give you more front end grip if nothing else is changed. So you have more room to play with stack, without having to keep it super low to keep weight on the front. So you can move your weight up, which helps body positioning, and bunnyhopping and manualing (as you're not folded over the front quite as much).

So for me, manualing and bunnyhopping feel about the same on my long chainstay bike, as my old short chainstay bike. But thats because my long chainstay bike has 20mm more stack, so I'm "starting the manual further into the process", so to speak.

But totally agree it is a factor to consider. Just saying its not been as noticeable as I thought it might be personally.
  • 2 1
 @ocnlogan: Don't forget that this increase in stack is eating into your reach (unless you are achieving the new stack with bar rise) The slacker the HTA , the more you lose with stack increase.
  • 1 0
 @DGWW:

Totally with you on that, but thanks for calling it out Smile .

I've got only 5mm of spacers, and a 38mm riser bar (I'm borderline between L, and XL, and went L), in an attempt to maximize the reach I have.

But that means I've got 20mm more stack from the frame + 13mm more rise from the bars, at about the same reach as my old short chainstay bike. So its not felt as much different to manual/bunnyhop as I was worried it might, thats all.
  • 1 0
 @ocnlogan: I've got an adjustable chainstay (425 - 441mm). I switched from 425 to near the longest setting about a year ago and would agree with you. The improved cornering stability outweighs the slightly harder manualling. After a while you get used to shifting your weight back a bit further.
  • 2 0
 Wouldn’t shorter cs only make it easier to GET TO the manual position. Once your there I’ve always felt that it’s all in the body position in relation to the bike weight (uneven teeter totter)everything is balanced on the rear axle and the cs length would seem to have more of a “minimal” effect at that point ?? Although a shorter cs would affect your available leverage to make real time correction I suppose
Probably why I cant manual very well lol
  • 2 0
 I've currently got a bike with chainstays at 495mm.... That is just too long. On bikes with chainstays in the 440 type length 8 can wheelie almost indefinitely.... On the 495 bohemouth I can barely lift the front wheel off the ground when riding.
  • 6 0
 @mattwragg why not mention that maybe...just maybe, our Front Centers are just too long? It seems like we are doing some mental/engineering gymnastics (shorter CS take the weight off axle?lol) to address a problem that's entirely possibly to be caused by the significant FC growth.

One takeaway is that quote about Levy 10 yrs ago and the Ripley. Whatever we say/think now, probably can't treat that like Gospel unless its been extensively tested with a proper sample size of people, track types etc.

Also, why are you on such a long bike at only 5-9? Hell even transition says you'd but on a medium Spire lol...with 455-460mm reach (albeit with their 35mm stem too...further shortening things).

Are we sure you aren't just simply riding a size too big??
  • 10 1
 This article title should probably have an "Opinion:" prefix
  • 8 0
 According to Evil short chainstays are the only way to have fun on a bike.
  • 4 0
 Here is a thought, different people want different things out of their bikes. I am glad we live in an era where there is a bike out there for basically everyone. I, for one, still love a short chain stay bike and am happy there are some companies out there still doing it.
  • 8 0
 Not everyone wants a plow bike.
  • 5 1
 I will say something that, by reading other comments, seems an "unpopular opinion", but here is a fact:
Chainstay length doesn't change bike's balance that much, if at all.
A big part of riding your bike is to move your CoG at the right place. So a longer reach gives you a CoG that will probably be a bit more forward, hence giving you a longer rear center, without adjusting anything. Maybe that'll put more pressure on your hands.
Everything in the article could be related to others factors, like suspension characteristics, tiredness, or the color of the bike. you are trying different bikes, you'll have different feeling.
  • 2 1
 To counter that, if a shorter chain stay requires you to lean forward more, and put more weight on your arms, more of your weight is going through a higher contact patch (grips) and the bike becomes twitchy and unstable. The benefit of a longer chain stay to balance longer reach is that the force through the petals is better balanced, and this is low and stable on the bike. This is generally good riding practice to push through your petals, and then especially in heavy corners, when a lot of your weight is pushing into the petals, the bike handles in a balanced way, rather than the rider being forced to try to push into the grips to get the front to grip.
  • 4 0
 I had thought short chainstays were the answer until I hopped on a bike with 425mm stays a few seasons ago—the thing felt frantic to the point where I lost confidence on the bike. So much so I'd slow down in chunky stuff and could never get my wight bias to feel very good. Went back to 430, then 435, then 437, and 444...lol. I am currently on a Banshee Prime, under-forked at 140mm which gives me a 500 reach and 65.5º head angle, and 450mm chainstays. At 6'1" I've never felt more stable and balanced. Which in turn inspires confidence, which leads to me being more playful. The bike just feels calmer, has a wider range of optimized body position, corners easier and faster and has more traction on steep, techy climbs. I know some of this comes down to suspension design and kinematics, but I think a huge part of the bikes stability and "calm" nature comes from the longer chainstays. I agree there is no single number in bike geo that is perfect for everyone, but I do think a lot of people could benefit from proportional chainstays as head angle get slacker and FC's get longer.
  • 1 0
 How do you feel in berms? I'm on a long-ass bike now too after having 425mm CS in my last bike. Feel like I have trouble getting the front of the bike to come around in the last third of the berm. Just me?
  • 1 1
 @Dogl0rd: Have you changed your riding position/technique since moving to the new bike? I went from a 34lb 2016 Transition Patrol XL with tiny 430mm cs to a brand new 42lb XXL Spire with 452mm and found that I have to be much more deliberate with my weight transfers left and right, needing flatter lean angles. Looking through corners and really turning your hips in the direction of the turn while pushing them to the outside helps as well. The longer and heavier a bike the more deliberate your inputs have to be, I like this because I am less likely to turn when I'm not wanting to.
  • 1 0
 @adamdigby: 100% I went through a few weeks of crashing early this summer before I figured it out, but yes. I ride way more over the front now. I think having to be more deliberate has been good anyway
  • 2 0
 @Dogl0rd: Yeah, I've been weighting the front end quite a bit more than I used to and pushing into the berm a little harder and later than I used to.
  • 4 0
 I think one’s riding style plays a huge factor in what chainstay length is preferable. I would love to see more bikes with adjustable length chainstays to help accommodate different riding styles. Not everyone is racing and not everyone sees the trail as endless features to jib around on. Allow riders to choose what suits them.
  • 7 0
 Ah, the old 'slow news day on a Friday fatally flawed pseudo technical opinion piece.'
  • 4 0
 Did anyone actually read this article?? As long as the marketing description says that the chainstay length allows me to jib, jab, be snappy and playful while keeping me planted and plowing through the rough stuff at speed who the F needs science.
  • 5 1
 If you can't think of ANY downsides for long chainstays, I doubt you skill as unbiased reporter. Seriously. Same goes for Aston MTB. Try to bunnyhop over 2 foot fence and you'll probably miss those snappy shorter chainstays. You can argue that mtb is not meant to do bmx things, but it's still a downside. And it's not hard to figure out if you are OBJECTIVE with your analysis
  • 5 0
 @mattwragg Slight exaggeration here - "The Forbidden Dreadnought ranges from 422mm to a whopping 546mm across its four sizes". XL tops out at 464mm
  • 3 0
 So you’re saying that there is a preferred ratio of RC to FC, but you have an actual number you prefer that isn’t a product of this ratio?

Yeah.

Horses for courses, but we all know there is no magic formula because every bike is different, every trail is different, every use is different , and every rider is different.

The fundamental flaw in this argument is:
bike manufacturers choose the chainstay length due to tire clearance. A longer chainstay is required for larger wheels (29 vs 27.5/2), a longer chainstay is required for bigger tires (2.5 vs 2.0), and a longer chainstay is required for more travel and for sone suspension designs.

So yeah, just another opinion from a non scientific rider who has an ideal that is based entirely in their experience.

Thanks for sharing!
  • 4 0
 PREACH! As a tall rider at 6'7" I really notice how a lot of brands, even those with size specific chain stays, don't go far enough to keep the ratios of front/rear center balanced throughout their size ranges.
  • 2 0
 That's because virtually every company optimizes their bikes for M or L. Everyone else is an afterthought. If rear center length and ESTA don't vary with size then the outlier sizes probably suck.
  • 1 0
 I'm 6' and it feels like the taller you are, the more the FC/RC affect you. I'm on a short CS 27.5 bike. It's super playful, but braking is sketchy in high speed, steep terrain.
  • 4 1
 Endurobro of course can't figure out shorter stays. They're not for plowing and racing. They're for jibbing and brapping. Get off the fast straight chunky trails and get into some tight trails where snapping and jibbing is Paramount. It's all about the front center length and trails you ride that determine the correct stay.
  • 3 0
 I actually went from a bike with a long reach/short chainstays (kona process 153 29") to something with way longer chainstays and similar front end length (forbidden dreadnought). Both are single pivots (although one is a high-pivot) so riding characteristics are not too dissimilar but the length of the stays has been a game changer for me. For sure the bike feels longer than the bike it replaces, but it also just makes it feel so stable. The rear wheel has a lot more traction on uphills and I feel more "inside" the bike than perched atop of it. At first I was afraid that the bike will feel slow and sluggish on tamer trails but it's been a pleasant surprise, it handles steeps and tight turns really well and still remains playful. Never has it felt cumbersome. I used to want the shortest chainstays possible for nimbleness but noticed that when they're partnered with a reach figure of over 500mm, they just sometimes feel too twitchy.
  • 3 0
 "I believe the next big step for progress is starting to have sensible discussions around chainstay length and to stop using descriptors like “nimble”, “playful” or “snappy” around them."

Then do it. We all dare you.
  • 4 0
 This is why i ride a stumpjumper EVO. for a large(s4): Its got a sensible reach and is very well balanced, No need to be over the rear axle or chest over the stem to ride it.... you basically hop on an go fast.
  • 1 0
 Same. One of the only bikes I could find with a reasonable front-rear balance. Railing turns takes much less energy, which means less mistakes over a long day
  • 4 1
 Chainstays/rear center should always be proportional to front center and reach.

However, short chainstay bikes with a long front end can be a blast. Not as fast, but easier to manual, cutty, and throw shapes in the air.

Like setting up a car for drifting, a short rear end is a blast…..but not as fast.
  • 11 5
 Pick a chainstay length and be a dick about it
  • 1 0
 pick a dick and be a chainstay about it
  • 7 1
 "More shorter, more funner. More longer, more faster."
  • 2 1
 More faster, more funner
  • 2 0
 Interesting discussion. I've looked at Antidote bikes' generally longer chainstays with interest; 450mm on their trail and enduro bikes. I'd assumed it was a design compromise to accommodate their suspension design (shock behind seat tube), but this discussion of a bike's balance does make the lengths seem sensible. Their Woodsprite seems to be an ideal bike to take on this, but it's relative newness means there's few detailed ride reports out there. C'mon PB i'm sure you guys can get one for a field test.
  • 6 0
 Shorter chainstays put MORE weight on the rear, not less.
  • 1 0
 Correct, it shifts your center of mass toward the rear wheel, which means to maintain front wheel traction YOU have to compensate by leaning forward. Multiply by as many corners as there are in a typical race and you're going to wear out your core and arms a lot faster.
  • 3 0
 Exactly, an article that starts off with that can't be taken seriously or even understood. It's one long misunderstanding. Every single argument is self-defeating because it starts from a wrong fundamental premise.
  • 2 0
 I have a giant e-bike with 473mm chainstays in size S and love it! I ride in the center of the bike. On the steep climbs, the front wheel is close to the ground and surprisingly it tractions very well. Sometimes the swingarm flexes a bit in corners but it's a fun feeling.
  • 1 0
 Yes, it's possible to love anything. Go figure! Nothing is more pathetic than guys telling you that you are "wrong" because you love this or that.
  • 2 0
 Thank god someone is finally saying this. Although Vorsprung pointed it out years ago when analyzing Sam Hill's Nukeproof compared to all the trendier bikes his competitors were riding-- his was short up front, and his riding style is notably muted and "sat back" in a more traditional athletic position. Much similar to Minnaar's stance, and he's also running the longest stays possible.
  • 2 0
 Great that someone "official" is finally pushing that topic forward. But I think you are only half way there. What dictates the amount of weight on each well isn't reach and chainstay length but the distance between both wheels and where your mass is on that line. Now once you consider that you start to understand why reach is a great metric to know how comfortable your attack position is going to be but how incomplete it is as a metric to understand front to back balance. Indeed the metric you need is front center because a 450 reach with 62 head angle will be as long of a front center as 480 reach with a 66HA. So for both bikes, if you want to acheve the same balance you will need the same rear center length so chainstay length as there is no extra component to that measure.
  • 2 0
 "Coming off a few years of almost exclusively running longer-chainstayed bikes, the first thing I noticed was the weight distribution. Initially, it manifested as less weight on the rear axle, so less traction." False. Moving the rear wheel forward puts more weight on it while taking weight from the front. While moving the rear wheel back takes weight off the rear and moves it forward
  • 2 0
 "Coming off a few years of almost exclusively running longer-chainstayed bikes, the first thing I noticed was the weight distribution. Initially, it manifested as less weight on the rear axle, so less traction."

What? Shorter chainstays will put more weight on the rear wheel.
  • 5 0
 Chris Porter has entered the chat
  • 4 2
 I can't stand riding bikes with actual short chainstays. I hate the lack of control and composure that happens on steeper climbs when the front wheel is barely skimming the ground.
  • 7 5
 Umm, learn how to ride?
  • 1 0
 jesus, id hate to see what you think about slack HTA then...
  • 1 0
 @sanchofula @HeatedRotor I have had this issue on every bike I've owned until my XXL Spire with a 62.5degree HA and 76mm rise bars.. I'm 6'5" and have a 39" inseam barefooted, if a bike has short chainstays and an average STA (which should steepen across sizes s-xl) I will be fighting the front to stay down on uphills no matter how far I wrench my upper body forward.
  • 1 0
 @HeatedRotor: my bikes are slack AF, 27.5 hardtail is 160mm travel with a 62 deg HTA, 450mm reach, and 430 CS.
  • 1 0
 @sanchofula: i was directing my comment at freetors.

@adamdigby I agree that on XL and over the CS needs to grow a little. But for anything under XL, no.

most large size bikes are pretty good if their reach isnt in XL zone like some are getting.
  • 2 0
 I think "playful" to a lot of people means less technique and/or effort in getting the front wheel up, and the loss of balance or stability in corners is taken as a challenge to tame a squirelly bike.
  • 3 1
 Rear center length (chainstay length) should be proportional to front center length across frame sizes. I think Norco and a few others are doing this already. This is the next trend in bike geo, and it's a good thing.
  • 2 0
 I think the idea of size specific chainstays has merit but anything above 450mm is probably excessive and I think if you start trying to match reach and stay numbers your bike is going to ride like a wet paper towel
  • 1 0
 I just got an XL Ibis Ripmo, which has a 500mm reach and 435mm chainstays. I do wish the chainstays were a bit longer. If I'm not weighting the front properly, I do feel it start to get light (though I ride in the desert and currently conditions are very sandy in spots). I don't remember feeling that way quite as much with my previous bike which had fairly similar chainstays, but a shorter reach.

I mostly notice it on fairly flat sections. When it's steeper, I'm somewhat automatically weighting the front, so it's not an issue, but a couple of times lately I've scared myself a little on the more open, flatter, faster runouts at the bottom of the trail. Part of that is me - as I relaxed more than I should have, part is the conditions as a heavier than usual monsoon left a lot of sand and small rocks on our trails, but part I think is the need to keep weight on the front more aggressively due to chainstay length.

That being said, I wouldn't want them that much longer. Maybe 445. I'm not an amazing bunnyhopper, wheelie dropper, slow speed bike handler to begin with and the short stays do help me on the tight, janky section of the trail at times.
  • 1 0
 Do you think having longer chainstays would help you weight the front wheel tho? (I'm an XL guy as well, curious as to your experience there)
  • 1 0
 @Svinyard: I can't conclusively say from experience as the bikes I've had are different in a couple of ways, but my new bike feels like I need to more aggressively weight the front wheel, and it makes sense to me that's related to the front end rear end ratio difference between the bikes. When I'm in a similar stance, a higher proportion of my weight is going to be on the rear wheel.

As I said before, it's not bad, I just am conscious of needing to move forward more on flat, loose turns and wonder if something with just a bit longer chainstays would make me less cognizant of that need.
  • 1 0
 @Svinyard: I took my old bike out this morning. I do think that the long reach has as much to do with the feeling of the new bike as the comparatively short chainstays.
  • 1 0
 @MarcusBrody: hey thanks man. That Ripmo is a badass bike without too extreme geometry (for these days). I'm guessing a couple months and it'll be second-nature with the updated body positioning.
  • 1 0
 @Svinyard: I suspect so! I've really enjoyed the bike so far. I didn't want crazy geometry, just a little bit extra security for gobbling up the chunky stuff we have here in southern Nevada compared to my gen 1 Bronson.
  • 1 0
 Reach is relatively less meaningful to this conversation than the "balance" between front and rear triangle lengths. And then there's the part about the "balance" between riders upper and lower bodies. People with long legs relative to their overall height (think Gazelle) tend to find that short chainstays put them too far back over their rear wheels. People with long torsos and arms relative to their height (think Ape) tend to find that they prefer bike that bias length more towards the front triangle.

And then there's the whole size/scale issue. Bikes tend to be developed in their medium/large sizes, and the very large and very small sizes tend to be just scaled up/down - chainstay length is one of those things that don't get scaled - but the same is true of the wheels. A 29" wheel feels very different to a 5' rider than it does to someone well over 6'.
  • 8 2
 Overthinking nonsense
  • 2 0
 IYKYK IYDKYDK
  • 5 0
 This article goes against what I love, short, snaptastic chainstays.
  • 1 0
 Chainstays length by size of bike seems more critical than a blanket “appropriate” chainstay length. I think my 22 Bronson could have more grip if it had slightly longer chainstays, but that’s not what I liked about it. It’s super easy to manual, whip, and I personally love to oversteer a little bit. It certainly can feel loose in the back around corners, but that just makes the same trails more fun for me.

Maybe trying to get timed laps and measure performance from bike to bike is why geometry is so critical to you. I think lots of us are just out to have fun. And race spec doesn’t always translate to fun.
  • 2 0
 With every new bike I gain more and more confidence and it is because, I think, we are getting the fit and geometry to be at a point where we are on/in the bike more rather than just hanging off the back like the old days.
  • 1 0
 shorter bikes were ok with 26 inch wheels and proportionate rear/front length balance. as wheels get bigger, you need a larger bike to balance it out.
i never thought this was a large issue or grounds to take a stance on.
companies of all different brands have been trying to find the sweet spot and good on them. like commencal went to mixed wheel size and actually extended their rear on the meta sx by 10mm and shorted reach 10mm to find that balance. a balanced ride is a predictable ride, especially if it fits you properly.
  • 2 1
 "Stability"/handling characteristics cannot be as simple as the chainstay length and reach: I ride a M/L 2022 Top Fuel and an S4 2021 Stumpjumper EVO. Chainstay lengths are 435 and 438, and reach numbers are 465 and 475, respectively, 465 for both if you factor I run a 10mm shorter stem than stock for the EVO. Almost exactly the same on paper. However, I corner far better on the Top Fuel than the EVO, especially when entering tight and steep berms. The EVO's rear wheel will fight me to lay it over into the correct plane to match the turn - to the point I am considering trading or selling the EVO frame to try something else. Doesn't seem like the difference should exist, given the similarities in geo. It is incredibly noticeable. EVO feels like it has 470 MM chainstays - on climbs and descents. Something else is at play other than the chainstay length. What is it?
  • 3 0
 Laying things over in a berm can be impacted by your stack height. I messed around with this a bunch and after dropping my stack spacer...IMMEDIATELY I was way more ripping and comfortable and aggressive in a berm. That high stack (I'm a tall guy on riser bars) I think had me a bit too upright in attack position...which perhaps led my weight to be a more to the rear. Once I fixed that stack, I was significantly in better control.

Top Fuel Stack: 600
Stumpjumper EVO: 639 roughly
  • 2 0
 Your story is similar to mine. I went from a 2021 Fuel Ex to a 2021 Banshee Prime/now Titan. I couldn't get the Banshee to turn, and it drove me nuts. I ended up doing some research on stack height and compared the two bikes. It turns out Trek runs pretty low stack on on their trail bikes, compared to some brands. I pulled 10-15mm of spacers out from under the stem on my Banshee and it was a night and day difference. When I moved to the Titan frame I measured my Prime's cockpit height and kept it nearly the same, minus the fact that the Titan naturally has more stack height and I'm running a longer fork.

I also have a 2022 Top Fuel and damn does that bike corner. I'm impressed with it's handling characteristics, considering the travel and shorter length.
  • 2 0
 @ZSchnei: Can't say enough good things about the Top Fuel! I had no idea stack height affected cornering that much - will move a few spacers around and see what happens. Thank you!
  • 2 0
 @Svinyard: Wild - had no idea. Appreciate the heads up... Will tinker with spacers and report back.
  • 1 1
 @Svinyard: yup I’ve found lowering stack forces me to bend knees and lower a bit more in the rear too, CG is lowered
  • 1 0
 I built a high pivot with 470mm static chainstays. The front end feels glued to the ground and is so easy to ride. I think I am more playful on it because I am less worried about the getting sketchy.

Insta: vessel_bike_project.
  • 1 0
 I have a Ripley af. Whatever voodoo they worked in there is pretty amazing. Aside from the stock fox performance suspension. Which is gone…. Jumpy and stable to boot. I’m riding the thing where my 160mm travel bike was appropriate. I only race my self and my smile indicator tells me it’s
A lot of fun to ride.
  • 1 0
 For all of us who have owned the perfect bike and didn't know why... we still dont know why. I propose CVCL, the continous varible chainstay length. Like a CVT transmisions will adjust chainstay length using an onboard AI computer running on 12 AXS batteries with optional handle bar manual shape shifting. Working on CVWTD ( continuos variable wheel and tire Diameter ) for 2025. You will see them on the canyon race teams soon.
  • 1 0
 That is why I bought an older Knolly Delirium (on Pink Bike Buy and Sell) in my current favorite size frame with sliding rear chainstay adjust so that I could find what I preferred for my riding style. Big headtube allowed me to play with HT angle too. I think the frame was 600CDN or so and it was also a great deal of fun to geek out on geo. like a test crew all by myself.
  • 1 0
 I agree with the idea of proportional chainstay lengths but disagree with everything else. This idea of a “balanced” bike seems ridiculous. Our bodies are not equal length or weight balanced. Do you want to have a bike where you have to do the least amount of body movement to get down the trail? Your chainstays are 10mm short, then move your hips 10mm forward. You can adjust your riding style to fit a bike and it will feel normal after a bit.

This feels like the trail building equivalent of making every trail a flow trail. Although with 450mm+ chainstays that’s probably all the bike is good for.
  • 1 0
 It's far more perceptible than the numbers suggest, especially in racing when you're in the saddle all day and pushing the limits of traction in every turn. Balance isn't ridiculous at all, finding the center of the bike is critical when cornering and a few cm fore/aft changes how much energy you're putting into bridging across your core/upper body vs your legs. "Long chainstays" aren't the solution in themselves, they are a necessary adjustment to exceedingly long front-centers. Having ridden a super stretched out 160mm enduro bike with a 430 chainstay I can confirm it's "playful" when you're f*cking around and awkward when you need to actually maintain exit speed in corners
  • 1 0
 Greg Minnaar rides longer than 450mm
  • 1 1
 @adamdigby: this article is not talking about DH bikes
  • 2 1
 @jlf1200: lengthening the chainstay moves the center of the bike backwards which would require more movement to properly weight the front wheel in corners. I think in general bikes are getting to long. I agree they should be proportional, but not close to the reach. I was referring to the article where he talks about chainstays almost as long as his reach. I had a bike with with 470 reach and 413 chainstays. I much preferred the super short stays on everything except super fast chunky stuff.
  • 1 0
 @adamdigby: he’s also almost 500mm reach. Assuming he’s 460 chainstay that’s 8% shorter. On my 450 reach bike 8% shorter would be 414 chainstay.
  • 1 0
 @wanabetrials: this is an interesting idea, to express the ideal CS as proportion of Reach, depending on application. 8% or 92% is a good benchmark
  • 1 0
 @rookie100: yeah, maybe not exactly those numbers but something like that. I just don’t think we need chainstay and reach to be equal.
  • 1 0
 @wanabetrials: Reach is not a good number to base the chainstay off of, front center is the better measurement. A bike with 520 reach and a 65 degree HA will require a shorter CS to feel balanced than the same measurements but with a 62 degree HA.
I did not interpret the article to not be talking about DH bikes, I read it as Matt's attempt to start discussion about chainstay lengths on all mountain bikes.
Lengthening chainstay while keeping everything else equal will do the opposite of what you say and require less effort to pressure the front wheel.
I am tall and have long femurs and feet, it's likely that I am upwards of 5" further behind the BB when I bend at the knees than the average medium frame rider. I believe an XL or XXL frame should have CS >18mm longer than a medium frame. I have also noticed on my new 55mm longer reach bike that I need the bars to be significantly taller having to purchase the 76mm tall bars and higher rise stem to feel anywhere near comfortable while pedaling and descending. Stack heights should have much larger gaps between frame sizes (some brands keep stack the same from small to XL and that's just silly)
  • 1 0
 "If the front or rear center is too short, this will reduce the bicycle’s stability whereas if the front or rear center is too long the bicycle will be less maneuverable"

Without sounding a know it all, I knew all of this statement to be true for years now since bs intro of LLS.

Anyways... Must be a slow day in the cough office cough ;d

& A good day for tacobell eat in place lol
  • 2 0
 Although some of the ideas about weight on the rear wheel are a bit funky, I generally agree about longer chainstay length being balanced with the reach.

But hang on, isn't this what Paul Aston has been saying for ages now?
  • 1 0
 two variables mentioned nowhere that have a huge impact on how the rear feels:

1) axle path. a long chainstay is one thing by itself. a long chainstay with a rearward axle path is a whole other animal.
2) rear wheel size. BB drop in relation to the rear axle has a tremendous impact on how the rear feels.
  • 1 0
 My old bike was a Jekyll 27.5 with a very short chainstay of 420 and long front end. Compared to my actual bike,a 29 Enduro with that long chainstay and more or less the same front end,it is like black&withe ride. The S.Enduro is really easy to ride stupid fast while felling no drama of any kind,the Jekyll was very happy to change direction but it ridding very fast felt like you were on the edge all time. Something in the middle I think it would be great for more enduro ride or racing,but for a fun bike you can throw whatever the S.Enduro is very good,I llike it way more than my older Jekyll.
  • 1 0
 With all respect to the author, who I'm certain is a vastly not skilled and experienced rider than I, I feel this article (yes, I read the whole thing) is basically just a "This is what I want and everyone else needs to want it too" manifesto, ignoring that there is absolutely no "normal" way to mountain bike. There are far too many variables in terrain, skill, body shape, ride preference, etc.

That said, the idea proposed of being able to select the CS that you want when you purchase your bike sounds great. I would be going 430 every time.
  • 1 0
 *more skilled...

stupid auto-incorrect
  • 2 1
 The obvious technical issues with this article aside, I feel like the conclusion of this article should really be:

Save your LBS and buy local; they exist so that you can ride a bike before buying it.

Somehow this writer has bike geometry fundamentally wrong (and gets paid for it), yet bike companies would have you believe that buying bikes blindly online is what's best. It's a lie: go, ride, find what's best for you, and support the local shop that enables you to do so.
  • 1 0
 I remember replying to this on Apr 2, 2022. Odd.

Anyway, switch to using ***CS length & WB length*** for balance, and you'll be closer to where you want to be. WB length figures in the reach, HTA, and also fork length and head tube length.

A 435mm CS bike will lack rear traction if the WB is very short (less than 1210mm). A 435mm CS bike will lack front traction if the WB is very long (>1250). Going by reach and HTA is lacking, as this difference in WB could be entirely accounted for by the fork length and head tube length, with the reach and HTA the same.

There's also other things to consider like a high pivot's chain growth and rider weight. A larger rider will have more weight on the rear, which requires longer CS to offset. A size XL will have a longer WB, mostly from the increased reach and head tube length, which also requires longer CS to offset/balance out.

Easy to make simple predictions going by WB and CS. I predict that a 440mm CS bike's balance will feel pretty good with a 1250mm WB. A 445mm CS bike with 1270mm WB should feel well balanced too... for every 5mm CS change, add/subtract 20mm WB to get a ballpark figure. For example, a Commencal Meta AM 29 in size small has 433mm CS and 1231mm WB, which I predict should have decent balance. A Commencal Meta SX in size med has 442mm CS and 1253mm WB, which I predict should have decent balance. If I were between sizes, I'd might notice the size med Meta SX is maybe a bit on the racier side, coming alive if I let go and get my butt back, my back flat, and chin behind the stem cap, while a large Meta SX feels radder, more willing to get airborne, at cost of reduced front wheel traction that makes it more challenging to carry race-level speeds through corners.

Going off of rear center (horizontal CS length) and front center would be even more accurate, but virtually all geo tables have WB and CS listed. Don't do division/ratios, like with FC:RC, as I don't believe it works. Validate using scales under each tire, and finding the actual weight distro, trying to use consistent positioning from one bike to the next. I recommend a neutral stance, where you're balanced enough on the pedals to not need to use more than a pinching grip (between the finger tips of thumb and forefinger) to stay upright.

Suggestion for next article: "it's time to pick bikes more based on WB length, rather than travel amount." How do you feel about having a two-bike quiver, both with 130-140mm of travel, but one is 1230mm WB and the other is 1170mm WB?
  • 1 0
 When reviewers review a bike I always disregard anything said about balance and nimbleness. It's because I usually ride a 420 to 435 reach which is far far away from the front centre rear centre ratio that the test size large bike is. We need a test in each size because they are all very different bikes. 22 Atherton reviews not coming soon.
  • 1 0
 At Crankworx Cairns Dual Slalom all the new "Slope" Hard tails with short as possible chainstays couldn't turn properly as the front would unweight when pumping with the legs. Older DJ hardtails with longer chainstays ripped out of the turns..
  • 1 0
 lol. Old DJ bikes have way short CS's. Go look at original BlkMrkt bikes Geo.
  • 1 0
 @Linc: I just look in the shed... 2 x Yeti Dj long chainstay, GT lopes long chainstay, Intense Tazer, long chainstay

when I say 'long' I'm longer then the modern Slope bike where the rear wheel is a close as it can be to the BB.
  • 1 0
 You're missing the word "style" there, and that's where the super short chainstays are aimed, not speed. But I bet even those "long" chainstay older bikes are still short by modern trail bike standards?
  • 1 0
 @G-Sport: yeah I would expect Modern trail bikes to have long CS than the OG DJs. I though it was interesting the difference between the SlopeStyle bikes and the DJs on the Slalom course...mentioned it because the forum topic was chainstay lengh discussion.
  • 1 0
 "Coming off a few years of almost exclusively running longer-chainstayed bikes, the first thing I noticed was the weight distribution. Initially, it manifested as less weight on the rear axle, so less traction."
After coming across this, it's impossible to continue reading. Where is the glitch? Is the error in judgment, in print, in writing? What's going on? There is no dispute that the shorter the chainstay, the more the rider weight is concentrated on the rear axle. So is the whole article one long... fluke?
  • 1 0
 "the rear would oversteer"

The rear can't oversteer by itself. OVERsteer means the whole bike is turning _more than expected_ for the provided _steering input_, and that input is the front wheel. So you need to consider both ends in any conversation about over- or under-steer.
  • 1 0
 I'd love to see adjustable chainstays more so different sizes are covered but also different preferances, riding styles and local trail types. Although i do sympathise with bike designers who spend alot of time balancing the suspension kinematics they want then have different chainstay lengths mess with it.
  • 1 0
 A very drawn-out and somewhat confusing analysis that still comes to the right conclusion: proportional chainstays need to be more common (though it is improving).
That means more molds, more SKUs, and likely a slightly higher cost across the model range, but it means bikes will perform consistently for different size riders.

I can read a review of a Ripmo written by a reviewer who is 5'9" and riding a size medium and it will ride completely differently for someone like me, 6'6" riding an XL (true story, tried that). We look so closely at front center numbers, seat tube angles (I have another rant about "virtual" vs "actual STAs), and HTAs that the wheelbase and chainstay length are often overlooked until I'm moving up a techy climb and CAN'T keep my front end on the ground because my tailbone is behind the rear axle in the saddle. An XL Ripmo will not perform the way a medium will, rider and terrain proportionate.

Cost-saving by using the same rear triangle across a whole model range just degrades the experience as you move further from the peak of the rider-height/size bell-curve. Huge shout out to Transition, Specialized, YT, and Canyon (to name a few, reply with your favorites) for making a full size-range of bikes AND having AT LEAST two rear triangles to accommodate the range.
  • 1 0
 "I have yet to find a coherent performance argument for shorter stays - I'd love to hear one." Manuals. It's the same answer to "What's the downside of reaches over 480 that provide great stability?" I'm 6'2" and like a 470ish reach and 435ish chainstay.
  • 4 0
 Wow the UCI really gets it. Such technical prowess!
  • 1 1
 I got a great argument against long(er) chainstays!
My 2015 Santa Cruz Tallboy almost killed me 50 times going down Whole Enchilada in Moab because of it’s 70°+ head angle and it’s 445mm chain stays.
So many drops into uphill faces- and I couldn’t wheelie off any of them! My 2021 Tallboy is worlds better all around, but still doesn’t like to wheelie on a steep downhill with it’s 445mm chain stay.
Luckily it doesn’t have a UDH, so I can shorten the chainstay for that ride. Go back to the long setting for most others.
  • 2 2
 I have found that a CS of 450-455 with 510-515 reach works well for me. Previously I have been on 440 FS bikes, 430'ish HTs and the likes.

CS should increase as the sizes increase, just to give the different sized riders the most similar experience of the bike (Stack should really also increase more than maybe 5mm, you can't tell me that the dude that is 6'4 only needs maybe 10mm more stack than the guy at 5'8, yes you can get higher rise bars to help with this).

I think that the most "playful" bike is the bike that feels the most balanced to you. At least IME then if you naturally have a neutral position on the bike (where both ends are weighed correctly), then it's very easy to throw your weight around and make the bike do what you want it to do.

On a sidenote, then being a XL rider I have for many many years delt with short CS that felt like I was seated over the rear axle and I am really happy that we have recently seen this wave of longer CS bikes
  • 1 0
 The Optic has size specific chainstays, and on my XL it's 440mm (17.32") on a 1275mm wheelbase. This *seems* perfect IMO - I can climb any trail I've wanted yet it feels balanced and stable through rough sections.
  • 1 0
 All this means is that the manufacturers have to build different rear triangles for the different sizes and that eats into profits. Hopefully market pressure drives them to do it anyway.
  • 1 1
 All know is I had a 2020 Giant Reign29r, great bike fun to ride but you had to pay attention to setup corners correctly. Now I’m on TranceX 27.5 & it’s to much fun to ride, ( high HT angle 64.5 ) just lean it over and rails corners better than the Reign ever did.
  • 1 0
 Aka, " your bike you just bought and really like sucks and is obsolete you need to sell it and buy a new one before its value declines" Pinkbike and the bike industry have this grift figured out.
  • 3 3
 Damn, I am tired of the unified editorial opinion on PB about geo. Even more tired of it continually being dressed up as revolutionary, despite being trotted out in almost every article. Loved that Seb Stott had to bring up chainstay length in a fluff piece introducing the new Atherton 130 mm bike. Glad we have experts to correct racing legends about what geo works best. Sorry PB, you're losing me with the insistence on beating this drum relentlessly. I want to hear a lot more details about bikes than you are giving. I hear a lot about the HTA, STA, and chainstay length. A lot less about how if feels to ride a bike. Contrast the Deviate Claymore's review here with the Loam Wolf's. LW gives a lot more useful information to me.
  • 4 0
 If I can manual and wheelie it it’s a good bike
  • 1 0
 If you really wan’t Seat Stay/Chain Stay/Travel/Wheel size/Geo adjustments to play with, then can’t think of a better bike than the Nicolai/Geometron G1. About as future and bomb proof as they get.
  • 1 0
 The autistic coming out was brave, and I respect you did it. But this here, is just laying down an overthinking delirium in words that really don't bring anything interesting to this topic I think.
  • 2 0
 The physics explanations above are wrong and misleading. Unless we're talking massive, steep grades, shorter chain stays will improve rear traction.
  • 6 3
 Pick a chainstay lenght and be a d..
  • 3 1
 If you make the chainstays longer (and the rest stays the same), you put more weight on the front, not less...
  • 3 0
 Grim Doughnut prt 2, the 500mm chainstay edition
  • 3 4
 I've been riding for 20 years and have tried different bikes with different chain stay lengths. I am a short rider being only 167 cm. I'd say riding skill wise I'm faster than most, but I do not count myself to the really fast guys.

From full suspension bikes I had banshee scream, balfa 2stepHD, commencal supreme dh (the on Gee had one his first races on), Giant glory 00, kona entourage, rocky mountain slayer and altitude, specialized spumpjumper, santa cruz bronson, norco aurum 2 generations and I probably forgot something. The reach was probably 400-420 on all of them.chain stays were 450-something on supreme being the longest and entourage with 414 mm being the shortest.

I used to not care about chainstay length at all until an eye opening moment. I had a giant glory 00, chain stay was about 440 mm and I tried my buddy's demo, chainstay was 420. It was eye opening how fun it was to ride, it was nimble, but stable nimble. super easy to bunny hop and to turn. since the I had a kona entourage, chain sty was 414! super fun bike, check out reviews on that, even on larger sizes.

so, to summarize. there are theories being created about ideal chain stay lengths, how front end got longer so the rear end needs to get longer etc. but I do not trust any of that because people like to make up things and try to believe them. why have we been riding such short bikes for so long? there were theories about perfect geometry back then too. for me, it should not be longer than 430 mm otherwise it get really hard to manual and bunny hop if the reach is somewhere in the reasonable range.
  • 1 0
 Yup, there were theories then, there are theories now, and there are more theories to come.

For years I ride trails on a zero offset mountain unicycle.

People would comment on how it must be really “loose@ in slippery surfaces.

Think about it, a single contact patch, you’re centered over the wheel always, pretty much the most stable ride on a slippery surface!

I gotta laugh at sone of these king chainstay arguments, maybe folks need to spend more time driving off road so they get a sense for how a longer vehicle acts; ie Wrangler vs Cherokee.
  • 3 0
 I like chainstays just the way they are.
  • 1 1
 It is simple physics: if you make only one side longer, the system gets out of balance. If you then add length to the other extreme, you get back in balance. Longer bikes must result in longer front AND back-ends.
  • 1 0
 Trying to get used to an ebike with 469.5 cs's after not riding for a few years and my last bike having 435's..definitley stable but I still can't manual it very well..
  • 2 0
 Cool, we’ve completed the 10yr bicycle lunar cycle, we’ve reentered the short vs long chainstay debate.
  • 2 0
 anything past 455 makes no sense to me unless you're riding in a straight line
  • 2 0
 I ride a Nukeoroof... I know at some point the chainstays will shorten themselves!
  • 1 0
 At least give Vital credit when you take from their forum (circa 2016) www.vitalmtb.com/forums/The-Hub,2/The-Internet-Was-Wrong-Short-Chainstays-Suck,9344
  • 2 0
 I am sure steep seat angles have nothing to do with less weight on the rear axle.
  • 3 0
 Turns out no one knows anything about geo.
  • 1 0
 Correct. Until the next loose fact comes out.
  • 3 0
 I won't even consider a bike with a chainstay length longer than 435mm.
  • 3 0
 Wow. This article is completely backwards.
  • 2 0
 "Its time...". It was time 4 years ago Razz
  • 2 0
 I feel like we need a pinkbike grim donut inspired bmx bike
  • 3 1
 You guys think wayyy to much. Get on and have fun.
  • 4 3
 Paul Aston is giving this concept a good crack already and seems to show it works well for him.
  • 3 0
 Yeah this was really surprising for me. He's gone to like 495mm reach and long ass chainstays for his Enduro style riding out there. But remember that's a fairly specific riding he's doing I think.

When you watch Jeff Kendall swap between long chainstay bikes (I think he did it with a mondraker), he lost some of the pop that he likes to ride with. At some point there's a trade off with long FC (as shown in his article) but also with RC as well as Jeff pointed out a bit. Where should we be in that balance? I'm not sure, but it'd be nice if someone could fully test and modernize some of the stuff Lee McCormick did and start to standardize bike fitment. Cause as you saw in the article, the bike has stability but its coming with significant fitment compromises. I think we are over prioritizing stability a bit these days.
  • 3 3
 Who cares?
  • 3 0
 @gabriel-mission9: Paul is an interesting guy because he's actually doing a bunch of prototype testing and going back and forth testing them with huge changes to his bikes. He's not just riding a giant bike, finding its wonky, and then hypothesizing about why the bike doesn't fit him right. Paul works with the manuf and gets custom stuff made for him. He's perspective is sometimes weird but at least he's legit prototyping his ideas and testing them.
  • 5 2
 Problem with Paul is he comes up with the conclusion he wants, and then bends the test to make it fit his preconceptions. This is not good science. But yeah, it's better than nothing, i'll give you that.
  • 3 0
 @gabriel-mission9: But consider this tho, he was all about super long reach bikes etc etc. Now he's on a bike with 495mm of reach as tall dude. That's smaller than almost every Manufacturer's XL bike. I think you are right that he's not doing science and he is preaching hard (or at least did) about what he was experience at that time and liked. I bet he's close to getting a clear picture these days having tested both FC and RC to the extremes.
  • 1 2
 @Svinyard: Yeah theres no denying the guy has a good brain on him, and has experienced many hundreds of bikes. There is certainly something to be said for that. He just needs to be less preachy and more objective. The whole episode with his setup in italy kinda says it all. He went and tried this totally mad idea with the totally unfounded confidence that it'd all work out cos he's paul aston. Then it all fell apart around him in a matter of months cos he didn't actually do anything to objectively make it work. He just lived the imagined dream and ignored all the ways the reality didnt fit what he imagined. Until the money ran out.
I kinda always got the same vibe from his reviews. He basically decides what he thinks is gonna happen before he's even ridden the bike, then approaches the review full of preconceptions. If the preconceptions don't fit the experience, then dammit the experience must be the thing at fault.
  • 5 0
 @gabriel-mission9:

Hi Gabriel. The project is still going. It didn't "all fall apart around me" but it's great that you know so much about my life. There was never any money to start with, so it didn't really run out. It just got very very difficult when I spent lots (for me) of money on all different kinds of bikes and every single one of them broke.

I think it's a good concept overall and the business is starting to work despite the difficulties of starting this during cvid times, changing countries, buying a house in a foreign language etc etc. If all the products I had bought had worked properly then I would have had many more positives to say and nice things to sell - unfortunately I can't say things are good if they are not and sell them to people.

Maybe it's a mad idea, but someone has to try these things, otherwise, I would just be another paid-for independent reviewer getting paid 4-10k per subjective review. This option was fully on the table (and would have been much easier and more lucrative for me) before I decided to try and do something more positive for the consumers and the bike world in general.

I was planning and still am planning to do more objective work in the future, but without a big budget or backers it's hard - I'm trying to get some dynos and other machines for the future. I don't see much objective work from any online reviewers/sites regardless of how much budget they have. If you want to help out and create something really special we can do something together: I have the space, time and platform. You can bring a 50-100k investment and we can start with a couple of dynos and start measuring stuff. From there I have designs to build jigs to test frame flex, wheel flex and full bike testing jigs too. Plus the space to build specific test tracks where we can test bikes on exactly the same features with my Stendec, BYB, or AiM systems fitted.

There have been some big positives from my independent testing model, though, as multiple brands have already changed and improved things off the back of my work. Now some MTB consumers like you guys will get a better product! Woohoo, that's what I like to see.

As for me being full of preconceptions and changing my review experience to fit: I'm sure we argued about my testing process and methods years ago in PB comments. I seem to remember I invited you to come and visit me in Morzine and do some testing together? That invite is still open if you want to come to the farm in Italy: buy and bring some bikes with you that you would like to test, we can test and film them together for my channel, then you can keep them or we give them away in a competition and get your investment back? If this works well we can discuss the testing ideas above in person. DM me for my phone number if you want to discuss further.

Cheers, Paul
  • 3 0
 @astonmtb: genuinely curious, which improvements have been implemented as a result of your work (/ by which brands)? Used to love reading your pb articles and big fan of your approach to mtb testing!
  • 2 0
 @scotteh: The main improvement was with Norco. They have changed their Ride Aligned Guide, torque spec sheet/manual, the pivot bolt design and product spec on the Shore models as well as shipping new bolt kits and some drivetrain upgrade parts to existing Shore owners. As well as saying they have improved and upgraded their entire testing and prototyping methods.

Banshee have done a running change on the Titan frame section I broke (and replaced my comp winners bike under warranty with no problems), though I think they knew that was an issue before.

Fasst Flexx are updating their website copy about bar geometry/suitability

Starling have modified/repaired all Spur frames



Unfortunately:

DT Swiss ignored me/the shop wouldn't comment on their broken shock.

Commencal and the top 15 MTB media (including this one) ignored me about Supreme frames cracking.

DVO, Fox and Ohlins ignored me publically about their products being shipped incorrectly assembled.


I'm sure there are some more bits and pieces too!
  • 1 0
 As last time dude, thank you for the offer but I have my own life and responsibilities to attend to.
As far as bringing a load of bikes to raffle off after we've ridden them, (aside from my ethical concerns with the whole buy-to-raffle business model) I fear I wouldn't get anywhere close to my investment back. This is my worry with the whole arrangement really. I honestly hope you can make it work, but it looks like a money pit to me.

Apologies if I was mistaken about the project being over. I ditched FB and Insta a while back so haven't been following, but was told by a mate who's a big fan of yours that you posted on socials that it had all come to a end, and you were selling up due to financial issues. Glad to hear it if thats not the case.
  • 2 0
 Pick a chainstay length and be a d!c about it!
  • 1 0
 Wait what? Shorter cs and you say it unweighs the back wheel? Shorter cs brings your weight bias REAR.
  • 1 0
 Great article! now i get why I feel more center and corner better on 1 of my bike.
  • 2 0
 @phutphutend
Can you please straighten out this mess Smile ?
  • 1 0
 It's actually "dribs and drabs" @mattwragg :-) Like, what the heck is a "drib"? Or a "drab" for that matter. ;-p
  • 1 0
 Dammit, yes, you’re right.
  • 1 0
 Which bike company will introduce on-the-fly chainstay adjustment first? This is the future.
  • 1 0
 Time for bb mullet bikes. Cs lengths longer than front center length.
  • 1 3
 @mattwragg

Very much agree with all of this. The more articles you write, the more things I find we agree on. Keep on being right about stuff, cos currently yours is some of the best stuff on PB.
  • 1 0
 Just whatever chainstay length Brage is using - get me on it now!!
  • 1 0
 I think whatever he's riding on only works if you ride >50mph 86.5% of the time your hands are on the bars.
  • 1 1
 Ebikes ahead of the game as usual with their long chainstays. Mainly to prevent them looping out whilst climbing.
  • 2 0
 Just go Ride Smile
  • 1 0
 I feel like the Rocky has a brake adapter on top of a brake adapter.
  • 1 0
 It's not size of the boat but the motion of the ocean.
  • 2 2
 People that know nothing about bicycle geometry should not write public facing articles about bike geometry.
  • 1 0
 Pick a chainstay length, and be a dick about it
  • 1 0
 26-inch rear wheel, non-boost axles, heavier stays.
  • 1 0
 HOW ABOUT NO
  • 2 2
 Fuck Yeah!!! Finally!!
  • 1 3
 I really don’t think 10mm is really going to do much
  • 1 0
 Ask your girlfriend.





You must login to Pinkbike.
Don't have an account? Sign up

Join Pinkbike  Login
Copyright © 2000 - 2023. Pinkbike.com. All rights reserved.
dv56 0.050585
Mobile Version of Website