Field Test: 5 Trail Bikes Face the Efficiency Test
PINKBIKE FIELD TEST
5 Trail Bikes VS the Efficiency Test
Words by Mike Levy; photography by Satchel Cronk
5 Trail Bikes VS the Efficiency Test
Words by Mike Levy; photography by Satchel Cronk
Pinkbike sent us to Whistler with five brand-new bikes and nothing but sunny skies and dry trails, so what did I end up doing? Climbing the same gravel road too many times, of course. We spent a ton of time on the chair lift, obviously, and we also did a lot of tricky, technical climbing while testing the bikes. This isn't any of that, however, because we also need to know how they perform when the onus is on your legs rather than your technical skills.
And yeah, I know I'm not wearing my lab coat and this won't get published in Science Journal, but that's not what we're trying to do. The goal here is to have a little "fun" while maybe learning a thing or three to back up our on-trail impressions, which is usually how it works out. All of the bikes were wearing the same Maxxis control tires set to the same pressures to help even the playing field, and the suspension was also set up for my weight across the board. And of course, not a single pedal-assist lever was used during the Efficiency Test.
Efficiency Test Results
1st Trek Fuel EX - 1:53
2nd Norco Fluid FS 1 - 1:54
3rd Santa Cruz Hightower - 1:56
4th Scott Genius ST - 1:58
5th Yeti SB140 - 2:00
1st Trek Fuel EX - 1:53
2nd Norco Fluid FS 1 - 1:54
3rd Santa Cruz Hightower - 1:56
4th Scott Genius ST - 1:58
5th Yeti SB140 - 2:00
Trek's Fuel EX was not only quickest in Kazimer's timed downhill testing, but it also won the Efficiency Test.
As usual, I had a set of Garmin Rally pedals and a 1030 computer to keep my power consistent, and our trusty Freelap Timing System served as the start and finish lines. The climb itself took around two minutes, with the first half being relatively low-grade that I stayed seated for before kicking up to that classic B.C. steepness for some out-of-the-saddle work at a lower cadence. And while the climb was short, the differences could add up to some much larger gaps over a long ride.
Question: You've just stumbled onto a duffle bag (or maybe two) stuffed full of money and it's time to replace your trusty Brodie 8-Ball with a new trail bike of some kind. How much of a factor does pedaling efficiency, or even just climbing in general, play in your purchasing decision?
The 2022 Fall Field Test is presented G-Form
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That said I still like the Norco
Does it climb? 15%
Does it Rip? 25%
Does it looks good? 10%
Will it last? 15%
Is it affordable? 35%
I may be in the minority but I love the more silly bits of the field test a la the impossible climb, efficiency test, and of course: huck to flat.
Do you mean "smooth" ground?
The question isn't which suspension design is better, the question is which one do you prefer for your riding style. There is no free lunch when it comes to suspensions in any sport. Baja trucks can carry high speed through crazy uneven terrain, but handle EXTRMELY poorly due to all suspension movement. F1 cars are extremely well handling, but have 25-80mm of suspension travel that is really only there to be able to ride curbing on the side of the track.
@8a71b4: It's true that the motion ratio curve and the anti-squat curve are what riders notice most about the suspension linkage. Shock properties play a large role, so it's more the wheel rate curve than the motion ratio curve, but let's look at only the frame, for now.
It's also true that multi-link systems can allow more control over the anti-squat curve. Broadly speaking, longer links produce more stable curves and shorter links do the opposite, so a LS configuration (ex. Horst) typically has less dramatic changes of anti-squat curvature than a SS. That's not to say a greater or lesser maximum value, though, nor more or less area under the curve. All systems - even single pivots - allow the chain to pull on the linkage, as you mentioned. The bike with the highest anti-squat on the market is a single pivot, the six bikes with the highest anti-squat represent five different configurations, and the six bikes with the lowest anti-squat also represent five different configurations.
There's some truth that no kinematic curves are universally ideal, but there's a narrow range that works for most people in most conditions, with most shocks. One of the things I do for my job is plot such properties for every bike on the market in the past 15+ years to analyze and forecast trends. There are clear convergences for regions of poor pedaling performance and good pedaling performance.
It's true there's rarely as much marketing put into LS designs as SS, but marketing effort does not equate to R&D effort or performance. There have been LS and SS designs that have been among the worst on the market, and both designs have been among the best. A kinematic curve with a sharper curvature or extra inflection point does not mean it's better, nor does it even mean these details are derived from the physics of optimizing ride feel and performance.
As an example, in the early years of Santa Cruz's VPP designs, they marketed their S-shaped axle path and claimed the chain tension would pull the wheel into a forward part of the curvature at sag, thereby always creating a restoring force and minimizing bob. Years later, their designer discussed how he realized the thinking was incorrect. First, the axle path, plotted on the 2D drawing plane, was not relevant; what was relevant were the vectors and torques about the instant centre. Second, the uneven chain tension and inertial forces from the rider caused a harmonic oscillation with the S-shaped axle path, amplifying bobbing - that's why early VPP bikes used such heavy low-speed compression damping tunes, to damp out the mess created by incorrect analysis of the kinematics. A lot of thinking, a lot of marketing, and more intricate curves combined to create a worse result. Santa Cruz has long since corrected their thinking and their design and their bikes now have excellent kinematics, but it illustrates how complexity isn't always linked to correct physics, let alone superior results.
Some SS bikes have more stable kinematic curves than some LS bikes. There's considerable overlap between the waviest LS curves and the straightest SS curves.
There's also an enormous range of values and curve shapes on the market. Even if it were true that designers of SS systems put as much additional time, energy, and money as you think into their designs (it's not), the fact that they've come up with such different results indicates they haven't used the SS design flexibility to get closer to the ultimate kinematics than what's possible via LS. It's not even a matter of different kinematics for different tastes; many of the curves have opposite curvatures and present truly divergent philosophies.
I'm not saying LS or SS is a superior configuration. I'm saying:
• SS is neither necessarily better nor necessarily more complex.
• Designers of SS systems aren't necessarily putting in extra effort.
• Not all designers know what they're doing, no matter how aggressively the designs are marketed. This was especially true in the past; thankfully, things are constantly improving, even if it's often by trial-and-error.
• The kinematics that people generally prefer show convergent trends in terms of both curve shapes and values.
I think the real magic of DW-links is that the anti-squat is intentionally derived from both rear wheel acceleration forces as well as chain forces. It feels much better when slamming into square edged things when under power, less fighting the pedals and more getting smoothly up and over without breaking rhythm. They have the "get-up and go" of a high AS design with some of the "tractor factor" of lower AS designs.
Yes, that's how Weagle does his calculations, but these forces have been built into Linkage software for years. Most kinematics designers use Linkage at some stage of their design work - often as their only tool for kinematics. Weagle did an enormous service to bike suspension design by laying out the design process in one of his patents. A few bike designers appeared to understand these things prior to Weagle's work, but many understand it now. (Almost all understand the principles of pedaling anti-squat and brake squat, but there's less understanding of wheel rate. Many designers still consider only the linkage kinematics.)
Even with an understanding of the physics, that still doesn't define the correct values to use. Weagle has always favoured higher than average anti-squat, producing the characteristic "crisp" pedaling of dw*link bikes. This isn't because Weagle's designs incorporate different forces - all designs are subject to the same forces, he just chooses to balance these forces more aggressively, at the cost of incurring more kickback while pedaling than some other designs. My own views are largely in line with Weagle's, but some clients prefer lower anti-squat to improve traction when pedaling and reduce kickback while pedaling, at the cost of incurring more squat when pedaling, especially when standing.
Some bikes have extremely high pedaling anti-squat (and, usually, kickback) early in the travel, then rapidly drop the anti-squat throughout the stroke to keep kickback as low as possible. SS designs have extra flexibility to keep the AS curve more flat in the pedaling zone, then drop sharply at the point in the travel when pedaling is assumed to be unlikely. Either way, it's a good strategy to tune the balance of pedaling firmness to kickback ... assuming we believe kickback is even a problem when coasting, but - as you said - that's a whole other conversation!
"all designs are subject to the same forces" Wait I was told that R3act 2 Play Naild silder suspension was magic that "broke existing paradigms about rear suspension performance"????
You've made an easy mistake, regarding R3ACT 2PLAY. It's not magic, it just harnesses the laws of physics in radically new way! Damping wastes energy, so it uses essentially zero damping - no damping equals no energy loss! It's so obvious that it's a wonder no one thought of it sooner.
As we dig deeper, we learn:
"The key to the system’s sensitivity and pedaling efficiency starts deep within the core kinematic structure."
And, from the R3ACT front suspension system:
"Even if you slept through high school physics, you likely know Newton's 3rd law which states that for every action there is an equal and opposite reaction. [...] Even the name R3ACT, with its "3" indicating Newton's 3rd law, provides a clue that this is a complete departure from existing suspension designs. And it is this concept of action and reaction that promises to forever change the way suspension is thought of and where it is applied.
Mockery aside, yes, the R3ACT 2PLAY rear suspension design is a great example of an unconventional design that goes to a lot of trouble - for the manufacturer and, potentially, the consumer - to achieve a negative outcome due to an incomplete understanding of everything that goes into creating an optimal ride experience.
Single pivot can have a strong starting anti squat, but it always gets lower as the pivot rotates (with the exception of Orange bikes, who have their single pivot pretty high and forward to essentially have >100% anti squat most everywhere, which makes for subpar suspension platform).
Multi link allows you to carry more anti squat deeper into the travel, which is what Yetis do.
Also, keep in mind that pedal kick is directly related to anti squat, since its anti squat in reverse. When analyzing anti-squat for bicycles, the only thing that matters is chainline growth. Acceleration anti squat, the likes of which is important for moto and cars, is almost irrelevant on bicycles due to the forces the rider provides. So high pivot designs usually have about 100% anti squat, since the chain doesn't really grow, and thus very little pedal kickback.
>All systems - even single pivots - allow the chain to pull on the linkage, as you mentioned
Not true. Concentric pivots like on some slopestyle bikes have next to zero chain growth, allowing you to run them single speed. High pivot designs with a small enough gear ratio also have next to no chain growth on the top part, so no pedal kickback, but they do have chain growth on the lower part (which is compensated for by the derailleur cage).
The highest anti squat bike isn't necessarily the one with a maximum value, its the area under the curve of >100% anti squat, in multiple gears. The only way you are achieving that is with a multi link design.
Anti-squat is an instantaneous value, which is why we need to discuss the anti-squat at a given point in the travel, for a given sprocket combination. With these things held constant, we can compare to bikes and the highest value is the highest value.
The area under the curve is a separate conversation. Your description of anti-squat being measured as "the area under the curve of >100% anti squat, in multiple gears" is certainly one way to consider the anti-squat properties of a bike, but it's not a formal definition. I would modify your definition in a few steps:
Step 1: Consider only the area under the curve for the region of the travel in which the rider is likely to be pedaling. No one is pedaling at bottom-out, for example.
Step 2: Apply a weighting curve to the properties according to the time spent in each sprocket combination and each part of the travel. If a rider mainly uses only a few sprockets when pedaling and spends most of their time at a certain point in the travel, those conditions are more important than other conditions.
Step 3: Modify the weighting curve according to how much each set of conditions matters. A rider may spend most of their time cruising at low effort at a certain point in the travel and using a certain sprocket, but this set of conditions may not be as important as shorter periods of extreme intensity with other conditions. More weighting can be given according to the importance of the conditions.
Step 4: Modify the centre of mass location according to the conditions described above. For example, most pedaling - and certainly most of the most intense pedaling - occurs while riding uphill, not on flat ground.
This produces a more complex, but far more accurate picture of anti-squat performance the the definition you provided. That said, it doesn't change the definition of anti-squat, which is just the instantaneous ratio of extensive to compressive forces on the suspension under a specific set of conditions, typically expressed as a percentage.
The useful output is the rate of travel up the hill. If we control as many variables as possible (ex. tires), we can assume the differences are due to the relative efficiencies of the bikes. So yes, the pedal is capturing what we want it to capture.
A thought experiment: Imagine a 100% inefficient bike that somehow dissipates all energy. The pedals will still record force and rotation speed, which allows us to calculate the input energy, just as we would do on a bike with normal - or even perfect - efficiency. The rear wheel is not turning, though, so there's no work being done at the rear wheel. Thus, the power meter at the pedal is more useful for this test than one located downstream of the drivetrain, which would include the hub or various systems that measure speed and altitude.
That's true but doesn't have much to do with suspension inefficiencies. Maybe I wasn't clear, the suspension movement comes from accelerations of the rider's body. Suspension doesn't just magically bob on its own from the cranks spinning at steady state. A person trying to pedal a bike waste energy unintentionally bouncing the suspension. That energy doesn't go to the cranks, it goes into bouncing the suspension.
youtu.be/Aq4yliFHBO8
It is conceivable that a bike could bob in such a way that it would smooth out the rider's movements and improve efficiency. I don't believe this will be the case, but it's not impossible. Some movements probably do aid efficiency, such as saddles that tilt a little, so it's not unreasonable to think a bike could do it. The point is that everything the bike does, whether beneficial or detrimental, is part of how it converts the rider's energy into forward motion.
The standard measurement for efficiency is to compare the useful energy output to the energy input. As such, we compare the forward motion to the rider's power output. Power meters at the pedals are the most direct measurement of the rider's power output other than measuring metabolism, which is possible, but impractical. Measuring instantaneous speed or time over a known distance is the most direct measurement of the useful work performed.
Thus, the system Pinkbike used is a pretty good measurement of the bikes' efficiencies, albeit on terrain that may not be an ideal representation of actual riding.
youtu.be/Aq4yliFHBO8
I encourage you to also watch the video. Steve says many of the same things I've been saying to you, such as Pinkbike's measurement system being good, among practical approaches, and metabolic measurement being the ultimate measure (again, ignoring whether the terrain is appropriate).
Steve does not say that a pedal- or crank-mounted power meter cannot measure suspension efficiency at all, only that it cannot account for some movements. For example, it is conceivable that a rider could have the most stable body possible and a bike could have an absurd suspension design that moves the wheel horizontally back and forth, with damping. The rider would not move up and down, all of the rider's power output would be captured by the power meter, and the enormous amount of energy wasted by moving the wheel forward and backward would be reflected by the poor time over the course. Thus, Pinkbike's system would capture that particular mode of energy dissipation through the suspension.
Similarly, if a suspension system raises and lowers the centre of the mass of the system with damping, that can be captured by Pinkbike's methods. It's possible for the rider's body to pedal perfectly smoothly, relative to the main triangle of the bike, while raising themself up and down due to bobbing. The energy dissipated into the dampers would be reflected in the change in time over the course.
Steve is one of the people I respect most in the entire industry and I almost universally agree with him, but this may be one time I don't. His example of the power meter reading zero when the rider is jumping up and down is sound because the rider's centre of mass is moving relative to the BB, thus doing work that is fully dissipated without forward motion. If the rider remains seated, without change in the CoM relative to the BB, and the upper body remains static, eliminating inertial effects, this unaccounted-for power is no longer a factor.
Also, Steve appears to have neglected the change in length of the chainstays due to suspension movement. This breaks the direct relationship between the pedals/cranks and the rear wheel.
You can mitigate this by seating down so the relative movements are reduced.
I'm glad we're in agreement but at no point did I say there were practical alternatives available for PB to use.
"It's possible for the rider's body to pedal perfectly smoothly, relative to the main triangle of the bike, while raising themself up and down due to bobbing."
No, the suspension isn't the source of the bobbing. Rider input causes bobbing. How much of the riders energy is converted into bobbing motion is determined by the suspension. Imagine you're driving your car down a smooth road at a constant speed...it's not bobbing up and down is it. That's because engines are much better at spinning circles. If you mounted a motor on your bike and did the PB efficiency test at a constant wattage at the crank you'd have a nice smooth bob free run. Have a human do the test without a motor at the same wattage and they would be wasting extra energy making the bike bob up and down while still measuring the same wattage at the cranks.
Both are sources of bobbing. The effective chainstay length increases as the suspension goes deeper into the travel, and chain tension pulls on the linkage in such a way as to shorten the effective chainstay, thereby resisting the suspension sinking into its travel. Ideally, the squat forces from acceleration are balanced by the anti-squat forces of the chain tension plus thrust from the rear wheel. The forces never balance perfectly for all riders, in all sprocket combinations, at all points in the travel, so the unbalanced portion of the forces cause a compression or extension of the suspension - i.e. bob. This is in addition to suspension movement from inertial forces of the rider's body movements.
A perfectly balanced motor with the same uneven torque profile as a rider would eliminate some inertial forces (chest and shoulders moving up and down, legs pumping, hips rocking, etc.), but the cyclical changes in chain tension will still cause suspension movement.
Why would a perfectly balanced motor have an uneven torque profile though? Not sure what your point is. Are you saying this uneven torque profile caused by the rider is well represented by the power meter while the rider is maintaining a certain wattage reading on the power meter?
The power meter will smooth this cyclical power output into a fairly constant moving average - no power meter would output the true instantaneous power, or else the numbers would fluctuate too rapidly to be meaningful to the user. The suspension, however, is exposed to these fluctuations through chain tension and horizontal acceleration of the system, which is a major source of bobbing.
Again, the example of the balanced motor is to eliminate one source of bobbing that is realistically possible to nearly eliminate, but retain the other source of bobbing that is not possible to eliminate.
And yes, of course no one thinks this test is a perfect measure of suspension efficiency. We're just exploring the physics of it and maybe finding small ways to improve the test.
Let's say the chain tension forces don't quite balance the squat forces acting on the suspension during acceleration, i.e. the increase in chain tension produces more squat from acceleration than jack from chain tension. Therefore, the bike squats a little more when maximum power is applied, then extends (and maybe overshoots) at minimum power. Some power is lost to friction and damping during this movement.
Similarly, if the extension forces from the chain tension exceed the squat forces from acceleration, the suspension extends during the maximum power phase and sags back down at minimum power (sometimes called "inchworming"). Opposite scenario, but same result.
This is why bike designers used to believe 100% anti-squat was ideal at sag, since the chain tension forces should perfectly balance the acceleration forces and result in zero suspension compression under any amount of tension. Most designers have since realized it takes a little more than 100% to balance the horizontal acceleration and the inertial forces of the rider's legs and upper body.
To complicate things further, the anti-squat force from the chain varies with the sprocket combination and the point in the travel, usually resulting in more anti-squat on flat ground (when there's less sag) and less anti-squat on steep climbs (when the rearward weight bias causes more sag).
Unfortunately, even a perfect anti-squat balance won't necessarily produce a perfect ride quality for all riders. The interaction of the chain and suspension involves a constantly changing virtual chainstay length. If another force is introduced via an impact at the wheel, it induces a change in chainstay length that disrupts the rate of chain movement - i.e. pedal kickback - and momentarily reduces traction due to a spike in torque at the rear wheel. Some riders would rather have less kickback and more traction, which comes at the cost of insufficient anti-squat to eliminate bobbing.
Every bike designer chooses a different level of anti-squat to chase the ideal balance of efficiency, traction, and smooth pedaling. Additionally, aesthetic and/or packaging considerations may require a suspension layout with an anti-squat curve that is not ideal for all sprockets and all points in the suspension. These factors create the differences in efficiency between suspension designs, and a portion of these differences can be tested with a pedal- or crank-mounted power meter and a stopwatch.
I’d wager that factors other than the frame/component spec make a bigger difference in this efficiency scenario, and probably your PB subjective impression is more important. There are some easy ways to make this test maybe more accurate.. but they’d be less digestible and less appealing to package as a simple climbing ‘test’.
Give a holler to the CyclingTips crew and have them do the climb efficiency work at the same time, link in PB article to CT test for the watt nerds. Single stone, meet 2 birds.
1. Why the flip don't you use the climb switches? This could be more than a novelty feature if it reflected how we actually ride our bikes IRL.
2. I thought one of the big deals about Yeti's fancy switch infinity gizmo was to provide optimum pedal efficiency at all times?
Generally sea-to-sky-corridor trails have little climbs sprinkled into the descents, with mellow grade forestry road climbs to get back up. Not to mention you're climbing in perfect refrigerator temperature weather. Lockout is very optional.
Other places I've ridden it was ratchet up steep singletrack then plummet continuously down, and hotter all over than the surface of the sun. Lock-out or fall over and become vulture food.
Every design claims this and they can't all be right. (Actually, none of them are right, though some are right-er than others.)
2. Riding position matters quite a bit in terms of body kinematics and how much power one can put down. I don't think the bikes were all compensated for same effective bb->grip stack and reach.
True, but perhaps these variables shouldn't be fully controlled. The different ergonomics are, to a certain extent, intrinsic to each bike and part of what defines each bike. Certainly the rider should make some simple efforts, like sliding the saddle along the rails and moving spacers above or below the stem, but if one bike has an extremely slack seat-tube angle and another has an extremely steep ST°, I think it's appropriate to let those variables affect the outcome.
Re: Yeti anti-squat
Yeti's pedaling anti-squat values were very high a few years ago. They're coming down, lately.
I know reviews tend to mention that they feel lively on the pedals though, and there's got to be some benefit to that hideously complicated liability
Every bike has unique kinematic curves, of course, and Yetis are no exception. Their curves are very similar to some other designs and could be replicated extremely closely by other designs. There's no magic in the Switch slider and nothing intrinsically unique about the kinematic curves Yeti has produced with it.
It's also important to consider shock tunes, which can vary more than the linkage kinematics. For example, some bikes use more than double the compression damping force (at the wheel) of others.
1: Yeti sales director flipping chart upside down walking into Projected 2023 Revenue meeting.
2: Intern just read text from head of sales: "bad fish tacos at lunch, going home, you can handle this, good luck."
if you're gonna gravel climb why not use the lockouts as most people would anyways
and find a nice steady climb in the woods to test them open mode
If every bike entered the 1st pylon at the desired wattage[330?] then I would accept the findings but the bikes start off in a race position that is dependent on the starting push and then up to speed.....that is the unknown variant i have trouble with.
And ya, I'm sure he wasn't faking how tired he was.
Equal mass is the right idea. I also recommend riding actual, representative trails. Efficiency in actual riding conditions is more than pedaling efficiency on smooth ground. Weight shifts, body movements, pedaling from standing, bump compliance - they all factor in to how quickly we can travel for however much energy we have available. Obviously, this presents challenges with repeatability, but it's important to consider both repeatability and relevance.
Average power VS time seems a good approach, but in reality, it is not. How distributed is the power matters a lot.
Imagine on a flat ground, someone putting 660W for half a minute, and then coasting for the same time. And someone staying still half a minute, and then putting 660 W.
Both would read 330W average power, but one would be significantly ahead.
If you want a useful data you'd need to consider something like "power input variation" VS "acceleration", with some smoothing to compensate for "elasticity". And you'd have to control slope at least, wind maybe. It would require much more maths & sensors than some clock.
you'd need a bunch of data point, and to model a bit to account for some parameters to see which one matters.
But there is some science you can probably do now: "blind" test the bikes at an average Joe's path, see there is not a statistical significant difference between them, and conclude that the prettiest bike is probably the best one.
That said, tires have terrible tolerances, so there could be some variability due to tire properties. If the takes takes a while to complete, the difference in temperature during the day could change tire rolling resistance enough to affect the outcome.
The slowest bike took only 6% longer to complete the course. An unfortunate stack-up of variations in drivetrain wear, lubrication, tire rubber thickness, tire temperature, bearing performance, etc. could account for most of the spread between first and last, let alone the differences between one position and the next.
Of course we can't hold bro science to 5σ scientific standards, but it's a fair point you've raised and we might as well try to do the best bro science possible at a realistic level of effort.
Something like the BB is almost certainly not worth the effort for two reasons:
1. The average differences in efficiency between one model of BB and another are part of the component spec. If a brand wants to win on value, they may have to take a hit on the performance of some components.
2. The differences in efficiency between good and bad units of a given model of BB are likely to be very small and the hassle of using a standard BB is very high.
Standardizing the contents of the rider's bowels is also unlikely to be of value because it shouldn't change much from one run to the next. Bladder contents might actually make a small difference! Second place was only 0.9% behind first, which equates to about 780 g. If Levy dropped 390 mL of ballast between testing those bikes, there's a 50-50 chance of changing the result to a tie.
The difference between a chain in poor condition and one in excellent condition could make the entire difference from first to last. It's unlikely the testers would accidentally allow such a disparity, but it shows the value of making some effort in this area, especially given how easy it would be.
The point is there's a lot of middle ground between doing nothing and being rigorous enough to impress a particle physicist. Some of the middle ground steps are worth the effort.
Meh, either way, the bikes are way out of my budget
Creates extra costs, weight, maintenance and performance.
The only purpose I see is EWS and DH.
Maybe you guys could do a shootout between a bunch of bikes priced for normal people: Wildcat, Fluid, Ripmo/ly and other bikes of the sort. Guess it's a value shootout, but the word value applied to a bike that costs more than a month salary for many riders doesn't seem appropriate
Yes sometimes we have to climb [gravel] roads, but it really shouldn't matter if one bike takes 2 seconds per minute longer or shorter on a gravel ride. If your riding partners insist on dropping you on the road climb because they're on a Trek and you're on a Yeti, then get new friends.
-It's important to me. A huge part of the reason I bike is fitness and I kind of brought myself to enjoy climbing over the years. I prefer dropping people to being dropped on climbs and I don't like to blow chunks - but I don't want to cross country. Decision making aside from price maybe 25% going up, 50% going down, 25% other factors like shop quality, aesthetics, stuff like that? very roughly
330W for 2 mins, 5 times over, Would love to know Mikes FTP as to hold that wattage consistently and repeatably he would be well under his VO2 max!
330W for 120s at 70kg (not sure what Mike ways but he isnt a goliath of a man) gives and FTP 63.3 (FTP of 289W or 4.12) which would be considered superior for any age for VO2max
climbapedia.org/VO2#:~:text=Peak%20Power%20Output%20(PPO)%20%3D,be%20estimated%20as%200.825%20*%20PPOPPO
Efficiency and weight are VERY important. Otherwise I'd just get an enduro bike.
That is why I would not buy any of those bikes, as they are heavier than some 2-4 year old aluminum trail bikes and I don't think they are any more capable. So if I'd find this cash and really HAD to change my bike, I'd go looking for something lighter than my current trail bike (13.9kg) without compromising its durability - and it would not be very hard, since my current trail bike has an alu frame and is a full XT build, so just upgrading the drivetrain would bring the weight down.
ABP didn't change the pedaling characteristics much: it's still a single pivot driving the axle path, only so much you can do with anti-squat. It did way more for braking, isolating brake forces from the swing-arm and allowing anti-rise to be tuned independently from anti-squat.
I never had the chance to try a 2011 5010.
To expand on what @justinfoil wrote:
For anyone curious as to why ABP (or Dave Weagle's equivalent Split Pivot) is Horst and not single-pivot with linkage-actuated shock, it's because the brake is mounted on a link that is not directly connected to the main frame. If the brake were mounted on the chainstay, ABP would be a single-pivot with linkage-actuated shock.
Thus, the motion ratio and anti-squat curves are the same for ABP/Horst and an equivalent single-pivot, but the brake squat (or "anti-rise") is different for ABP/Horst and an equivalent single-pivot.
ABP and Chainstay Pivoted suspension????....
Swingarm
Swingarm w Linkage
Swingarm w Flex Linkage
Horst
Horst w Linkage
Twin Short - Co-Rotating
Twin Short - Co-Rotating w Linkage
Twin Short - Counter
Twin Short - Counter w Linkage
Lawwill
Lawwill w Linkage
MacPherson
iDrive
Slider
6-Bar
There is a menagerie of 6-bar types and I include flex-pivot Horsts (ex. Cannondale) with Horst, so it's not a perfect list, but it suits my needs until 6-bar flex-pivot designs take over (kidding ... I hope).
Another way to look at it - one I've been using as much as possible, recently - is to divide four-bar systems into LL (two long links, such as Lawwill), LS (one long and one short, such as Horst), and SS (ex. VPP, dw*link, etc.). My goal is to demystify suspension design and highlight the commonalities between them.
To go back to the original examples of Trek's ABP and Specialized's Horst, I think an efficient description for both is LS 4-bar ... followed by hours of discussion of the different kinematic properties, shock tunes, fit, and handling, of course!
ok, LS 4-Bar is an efficient description for both. Can you come up with an efficient description for each?
thnx
If we agree to various parameters, such as the point in the travel at which to compare, the centre of mass location, etc., I can tell you things like "for the parameter in question, Bike A was at the Xth percentile among bikes in its category at the time of its introduction, and would be at the Yth percentile today" or "Bike A had X% more anti-squat than Bike B for the specified rider and conditions".
To try to give a useful answer, the pedaling anti-squat of both the Fuel EX and Stumpjumper have always been well below average among their peers. That's not to say this is a good or bad thing, nor to equate low anti-squat with low pedaling efficiency (it's certainly more complicated), just that's how their anti-squats were configured. Their anti-squat values have both increased with newer generations.
Specialized has used particularly light compression damping and flat motion ratio curves, favouring less sag, which could help with pedaling efficiency. Earlier generations of the Fuel EX had more progressive MR curves, but still pretty mild, with more focus on low-speed compression damping.
They've always been very similar bikes, in the larger picture. If we compare them to something like a typical Devinci or Pivot from a few years ago, or a MY2018 Kona Satori, the difference in pedaling feel is stark.
Looking at the current versions of each, they're still very similar. The Fuel EX has ever-so-slightly below average anti-squat and the motion ratio curve is similarly slightly less progressive than average. The Stumpjumper is much like its predecessors, while the Stumpjumper EVO is similar to the Fuel EX, with ever-so-slightly above average anti-squat and a motion ratio curve that's about spot-on average. They're both models in the middle of the bell curve category, aimed at the middle of the bell curve customer, and have middle of the bell curve kinematics. Their product managers and designers understood their assignments and executed rather well.
If I'm interpreting you correctly, you seem most bothered by me calling ABP a special case of Horst. No one is saying Horst is the best term for ABP, and don't worry, I don't go around calling it a Horst. The point was to illustrate how ABP is equivalent to a Horst with zero offset, which it is.
You said:
"it's still a single pivot driving the axle path, only so much you can do with anti-squat. It did way more for braking, isolating brake forces from the swing-arm and allowing anti-rise to be tuned independently from anti-squat."
True, but it's not the best way to explain the situation to say it's like a single-pivot with extra degrees of freedom when we already have a different class of linkage for that. They're both four-bar linkages and ABP is just a special case of the four-bar - specifically, the trivial case.
If we start with the most basic single-pivot, it's a swingarm, like a classic Orange. We can add features to control kinematic parameters (axle path, motion ratio, pedaling anti-squat, brake squat.) In the case of your floating brake, that's a separate linkage that controls only brake squat. We could add an indirect drive to control only the anti-squat. We could add a linkage to drive the shock to control only the motion ratio. These are all still single-pivots, with additional mechanisms.
A four-bar system allows the designer these degrees of freedom in an integrated package. The designer may choose to not use every available freedom. For example, a linkage could have an instant centre that does not move and a motion ratio that matches what's possible via a simple swingarm. This would be an unusual configuration, but it's still a four-bar. Similarly, ABP is still a four-bar, even if the designer has chosen to eliminate a degree of freedom by reducing one dimension to zero.
This is why I've been using the LL, LS, and SS terms for four-bar linkages. The goal is to demystify suspension by showing grouping them together as different configurations of the same thing. Maestro isn't a fundamentally different thing from dw*link, or Horst, or ABP, or KS-Link, or Lawwill, or Switch Infinity, or ... None of these systems is capable of doing anything the others can't; it's the designers' choices of how to tune them. Compared to a single-pivot, however, they can do extra things. Whether these extra things improve our ride experiences is up to the skills of the designers.
@Narro2: I care enough about the topic to explain it thoroughly. If that doesn't suit you, it's your choice whether to read it.
yeah I am not reading them.
Still kudos for the passion my friend.
You intrigue me.
Careful with generalizing, I did read and was intrigued of the first ones, but you know when was the moment I stop reading them.
Really I intrigue you?, a person so knowledgeable and smart about bike Concepts/Ideas, does not have the self control to not focus on People (especially the ones on the interwebs)?
P.S. That was your longest reply.
Somehow, that makes no sense .... oh right, this is roadie content!
I thought I turned that filter on, damn.
And to answer the question, I don't need my trail bike to climb fast. I need it to climb well over the technical stuff.
Trash test.