Nerding Out: Why You Shouldn't Worry About Pedal Kickback

Dec 22, 2021
by Seb Stott  

At World Champs in 2014, Neko Mulally snapped his chain out of the gate but went on to score a career-best 4th place. The following year, Aaron Gwin snapped his chain in Leogang, and he went on to win. After crossing the line, he could be heard saying "The suspension works so much better without a chain."

How can we explain this? It's obvious, right? Pedal kickback.

Credits Marco Piffari
Gee Atherton s neutral gear mechanism. The idea here is that on rougher sections of track He d shift into the dead gear to eliminate pedal feedback.

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There are all sorts of devices designed to eliminate pedal kickback, but do we really need them?

In virtually all suspension designs, the rear axle gets further away from the bottom bracket as the suspension compresses - that's because the main pivot is above the bottom bracket. This causes the length of the chain span from the cassette to the chainring to increase, which is known as chain growth. If the suspension is compressed while the rear wheel doesn't rotate, the cranks will be forced to rotate backwards through a certain angle because the cassette moves further away from the chainring. This is pedal kickback.

If the suspension moves through its entire travel without the wheel rotating, the cranks would rotate backwards by an angle that can be as much as twenty degrees or so, depending on the suspension design and the gear selected. Generally, bikes with more rearward axle paths and therefore higher levels of anti-squat will have more chain growth and therefore more pedal kickback.

Hucking

It's often said that pedal kickback leads to harshness, feet being blown off pedals and restricted suspension. But pedal kickback is more of a theoretical calculation than a real-life phenomenon. When riding, the crank doesn't usually rotate back to allow the chain growth; the cassette rotates forwards. As long as the wheel is spinning at a reasonable speed, it's very easy for the cassette and freewheel to rotate clockwise, which allows the suspension to compress without the cranks rotating.

You can see this in the below huck-to-flat video. Here the bikes are going quite slowly and the suspension is compressing pretty fast - quick enough to reach bottom-out - yet the cranks don't rotate backwards. In fact, the chain has enough slack to wave around and sag under its own weight. For the chain to rotate the cranks, it would need to be taut which would make it roughly straight.


There are situations where the wheel may be rotating so slowly and the suspension compresses so quickly that the cassette and freewheel "catch up" with the wheel speed and so cannot rotate any faster, in which case the chain will become taut and apply a backwards torque on the crank. You can feel this if you land a drop to flat while travelling at a very slow speed.

But even in a worst-case scenario - a bike with a lot of chain growth, the suspension compressing at a particularly high speed (five meters per second), and the chain on the smallest sprocket so the wheel has to rotate further to spool out enough chain - pedal kickback is impossible when travelling above about ten miles per hour or sixteen kilometres per hour. Remember that's a worst-case: for most combinations of bike choice, suspension compression speed and gear choice, the minimum speed required to avoid kickback is much slower.

I'm not saying that pedal kickback never happens, but it's what you might call a corner case, a rare combination of circumstances. You certainly can't blame it for repeatedly blowing your feet off the pedals on a rock garden.

Braking

In the opening shot of this video you can see the rear wheel lock-up when it's in the air, but it starts rotating almost as soon as it lands.

One exception to this is when the rear wheel is locked up (skidding) while riding over bumps. Even for experienced riders, lock-ups are common, especially on rough terrain, and while the wheel is stationary pedal kickback could come into play. But lock-ups usually occur when the wheel is unloaded, for example on the back-side of a bump or step, and the suspension isn't compressing in those situations anyway. When the wheel hits the ground hard enough to compress the suspension by a meaningful amount, the wheel usually has enough grip to start rotating again. Sure, there will be times where the suspension is trying to compress but there isn't enough traction to get the wheel spinning (panic-braking on slippery, rough terrain), but this is another corner case, and you probably have bigger problems in those moments. To be fair, even a slight lag in the time taken for the suspension to start compressing freely could be significant, but based on the many bikes I've ridden I can't say I've noticed the ones with more chain growth feel harsher when braking.

Pedaling

One area where bikes with high levels of chain growth can perform worse is when pedalling over bumps. That's because the change in the length of the upper chain span as the suspension compresses can upset the pedalling rhythm, and because the chain tension caused by pedalling can restrict the suspension from compressing. On the other hand, high chain growth means higher anti-squat, which improves pedalling efficiency up to a point. Bikes with an idler pulley (and therefore minimal or no pedal kickback) do tend to pedal more smoothly over bumps, but the idler compromises drivetrain efficiency which is less than ideal if pedalling is a priority. Meanwhile, many of the other devices designed to minimise pedal kickback (like those pictured above) don't work when pedalling anyway.

2015 Specialized Demo
2020 Specialized Demo
In 2019, Specialized switched from a design with very low pedal kickback levels but a very forward axle path (left), to one with more pedal kickback but a better axle path (right).

Conclusion

The reason why bikes with a high pivot and idler pulley perform better in chunky terrain isn't so much the lack of pedal kickback, but their more rearward axle path. For bikes without idler pulleys (most bikes), having a more rearward axle path inevitably means more pedal kickback, so bikes with more pedal kickback may perform better in the rough. Ultimately, the amount of pedal kickback a bike has is just a side-effect of how much anti-squat it's designed to have and isn't something that affects performance much in itself.

So how come World Cup racers ride faster without a chain? I think the main answer is they don't. Snapped chains aren't uncommon and almost always result in a disappointing race run. Gwin and Mulally are memorable exceptions, and tests have shown that not pedalling can be a good strategy on downhill runs even with the chain on, because the energy saved can be better used on the technical sections. Sure, the chain slapping around wildly could create additional vibration and the derailleur's clutch might impede the suspension movement (very) slightly, but even these effects aren't directly linked to pedal kickback, so fitting your bike with a neutral gear or a slower-engaging hub won't solve them.





169 Comments

  • 148 1
 I’ve always been suspicious that those chainless DH runs that have been so fast have actually happened because the rider is all of the sudden super focused on riding as smooth as possible because they won’t be able to pedal on the flatter sections.
  • 43 6
 I think also, for a fined tuned racer, dropping the mass of the chain may improve suspension feel very slightly and the lack of noise creates the placebo effect of increased smoothness and traction
  • 10 2
 @superkeen: I trashed my mech in morzine one year. Had to take it and the chain off to enable the bike to roll. Had the nicest feeling ride down the Pleney black run. I attribute it to the loss of unsprung mass rather than lack of pedal kickback.
  • 5 0
 @AyJayDoubleyou: What people forget is even if small things like that improve suspension by small percentages those small gains are still felt.
  • 24 0
 100%. In particular I think Gwin's famous run proved just how important carrying exit speed through corners and conserving momentum was (at least on that particular course). All of a sudden he was like "whelp, this is the only thing I have to work with on this run so I better maximize it" and it paid off.
  • 2 0
 @nilswalk: totally agree. Try switching back and forth from single speed to geared and see what it does for your riding style
  • 1 0
 @nilswalk: agreed. If it happened on the first pedal at the start of a flat section he’d be done. It’s the luck of it happening once you’re up to speed on a track that really doesn’t need much pedaling.
  • 2 0
 @Mike-Jay: didn’t he snap the chain on like the fourth pedal stroke out of the gate, or am I thinking of another one?
  • 1 0
 @jaame: yep. But he’d already got those first three big pedals in to get him to the steeper roll in.
  • 1 0
 @Ghamel: I've felt the suspension smoother when I forgot the clutch open. until I realised the chain jumped some gears.
  • 2 0
 There’s also less drag from the freewheel, though I can imagine pros have less drag on race day through o-rings removal and maybe special lubricant? Anyway, it will be more than no friction, no matter the improvements.
  • 1 0
 Plus, you'll also consciously brake as little as humanly possible...
  • 1 0
 @krka73: It's just like riding a single speed. Once you start descending you pretty quickly run out of gear and can't pedal.
  • 1 0
 @Mike-Jay: lol 3 pedal strokes
  • 1 0
 i assumed it was a combination of a few factors
  • 87 0
 But you guys told me I need to worry about that
  • 24 0
 Just get a hardtail
  • 40 2
 @jackdwalker: and a rigid single speed.

You know what, just trail run.
  • 60 0
 @hamncheez: wait so if you trail run do you just carry the chain or what?
  • 31 0
 @bkm303: yes, but be careful it doesn't dangle out of your pocket. If it drags on the ground it will create inefficiency and slow down your jogging.

I sell a product, called O-band, that's a rubberized, elastic device to better hold your pocket chain while adding minimal drag.
  • 12 0
 @hamncheez: Nope, nope, nope. Trail running is way worse then mountain biking when it comes to insane nitpicking. Even when it comes to efficiency though rough terrain. example: I could run with a comfortable shoe with plenty of support, OR I could run with this expensive, semi-transparent "sock" that has 2mm of rubber glued to it because it weighs less.
  • 1 0
 lmao
  • 1 0
 @jackdwalker: yeah, my hardtail told me once that only my legs had to deal with kickback effect... and my hardtail is always right Wink
  • 3 0
 @hamncheez: *trail run naked and barefoot for maximum efficiency and lowest unsprung mass.
  • 12 0
 @bananowy: nobody wants to see that unsprung mass.
  • 5 0
 @fruitsd79: Oh, it's sprung; don't you worry about that!
  • 6 0
 @bananowy: that only works when you are young: for an older runner, the efficiency loss when your balls keep bouncing off your knees is far too high.
  • 70 0
 High pivot with no chain is obviously the race-winning setup no one is talking about.
  • 41 2
 low pivot with two chains is the real secret no one's talking about
  • 10 2
 Close. It's High Pivot, no chain, and mullet.
  • 14 0
 @BobbyLite Instructions unclear, which bike has high chain no pivot? Thx
  • 5 0
 @BobbyLite: insert picture of 2 chainz riding a bike…
  • 2 0
 @txcx166: well... ignitestudentlife.com/wp-content/uploads/2021/08/giphy-25.gif

Bit of a missed opportunity on his part. Should have ridden a tandem with um... 2 Chainz.
  • 1 0
 @bananowy: haha. Nice.
  • 45 0
 I bet that Gwin probably used the brakes less than planned on that winning run as he knew he wouldn't be able to regain speed by pedaling. He probably pushed the limits more than usual that day....
  • 21 0
 also he was in top form then like the entire season was on fire
  • 8 0
 @madmon: there was an additional theory at the time - on the motorway jumps section the wind had changed since practise. Everyone pedalling like crazy was coming up long and landing to flat. Whereas gwin coasting / speed tucking ended up at the perfect speed to land on the transitions.
  • 9 7
 You also forget, he’s a religious man. Maybe that helped.
  • 15 0
 He also has run a chain every race since……
  • 14 5
 Aaron Gwin: "The suspension works so much better without a chain."

Everyone else: "Suspension didn't feel any better on his run, it was only fast because blah blah blah..."

Rolleyes
  • 6 0
 @madmon: he might have won by even more with a chain.
  • 1 0
 @mobiller: Specialized:
“Bye bye Aaron”
  • 3 0
 @mobiller: I had to remove my chain before a 3k foot descent once due to a seized hub. The suspension worked soooo much better. It isn’t a little thing it’s night and day. I don’t have a mechanical explanation for it but that experience won’t allow me to agree with this article
  • 3 0
 @Mtmw: Yeah for sure. I busted a chain a few times and descended chainless, once very recently. Improvement in suspension performance was just ridiculous.
  • 1 0
 100%, the fastest guy down the hill used the brakes less than everyone else.
  • 38 4
 Can we conclude that “pedal feedback” is just something slightly annoying at times? I’ve never had massive kickback, but do find the occasional tension on the drivetrain to be less enjoyable than when there isn’t that feeling.
  • 23 2
 I don't have any statistics to back this up, but I feel as if higher engagement hubs bring more pedal kickback, which could also make it more annoying.
  • 5 1
 @Thendeb: you may have a point.

Just shows that bikes are not binary but about so many variables which is what makes needing things out without all the variables in the equation, not so needing but hypothasisng (if that's even a word).

In reality it's about what the clock says and setup over textbook theory. (it's what separates engineers and scientists).
  • 2 1
 @betsie: Yep! There are so many variables at play here. In the end, you're right about the clock being superior to textbook theory.
  • 3 1
 @Thendeb: It definitely will because there is less dead space between engagement points. The faster the suspension compresses and the higher the hub engagement, the more pedal kickback you will feel. It would make sense that higher anti-squat values would also add to that since you're using chain tension to keep the suspension from compressing. The only time I have ever had kickback issues is on my full suspension bike while climbing rooty and rocky sections in very low gears (1'st or 2'nd).

If you're really worried about it (which you shouldn't be), just ride a hard tail Smile
  • 1 0
 @Thendeb: They do. Your right.
  • 4 0
 @Thendeb: Totally agree. I have some Onyx hubs and this is one of the first things I noticed about them in technical climbing situations. They also ratchet back more when you're rocking/hopping.
  • 5 0
 @Thendeb: The very first thing i noticed when i went to a 102t hub was How much more feeling you got through the pedals, to prove this wasnt just me being dumb i put my old wheel back on and it instantly "smoother" especially in the rough fast sections.
I now run low engagement hubs at the bike park and high engagement everywhere else
  • 1 1
 @betsie: non-binary bikes are the best kind of bikes
  • 2 0
 @Thendeb: as long as the wheel is spinning at a moderate speed, it doesn’t have any affect.

youtu.be/grNUgu0H9YA
  • 3 0
 I find modern suspension design so good that I don't need to "ratchet" my pedals anymore in slow tech sections (shorter cranks helps) so I went back to lower engagement hubs. Suspension works better now.
  • 4 0
 @Thendeb: Very true! Another variable is gear selection. I like to run on the biggest cog to reduce my pedal kickback.
  • 1 0
 @JohanG: ya but you need to ratchet to clean difficult tech climbs. Engagement has no affect - youtu.be/grNUgu0H9YA
  • 1 0
 @TurboDonuts: suspension design plays a part in the gear gear selection descending theory as well as chainring size. Especially if you have a pivot near the axle.
  • 2 0
 Pedal feedback is anoying, just the chain bouncing around creating all that chatter is something that can be improved, but not by more chain, but the lack of it.
  • 1 0
 @TurboDonuts: then you're doing it wrong. Many designs have lower/lowest chain-tension-based anti-squat in the big cog.
  • 1 0
 @justinfoil: I'm trolling Smile

Happy Holidays!
  • 22 0
 There is a lot of psychology involved in bike suspension performance. Seb’s conclusions are all correct for the load cases he’s covered, ie if you have any kind of freewheel system it isn’t really an issue for large single inputs while coasting. We do however see torsional vibration transfer to the pedals due to the cassette, mech and chain all slapping about (often in resonance) over rough surfaces. In this scenario you will feel less vibration at your feet with some sort of isolator (o-chain) or with the chain removed. A lot of people will relate less vibration at the pedals to “suspension working better”, others will ignore it.
  • 5 0
 100%. Take a dirt bike for instance. In neutral rolling down a hill, the suspension feels different motor off vs running. Though in reality the engine has zero effect on the suspension in neutral.
  • 16 1
 @seb-stott
Great Article as ever, dispelling marketing bullshit.

But there's was one throw away comment that needs validation: "high pivot bikes work better because of rearward axle path". Personally I'm not convinced by this, I think the maintaining of wheelbase effect is more important.

Maybe an article in there somewhere...
  • 4 0
 Thanks!

How much of a benefit a rearward axle path (as opposed to a mostly forwards path of a conventional bike) offers is definitely debatable, and I think it's often overblown, but I actually said they "work better in chunky terrain" - I think there is some benefit on large, square-edge hits. I'm not so sure about the conservation of wheelbase per se, but the longer rear centre at sag definitely has a benefit in terms of front-wheel traction. Maybe we just need longer chainstays?
  • 12 0
 So this morning I read high pivot doesn't make any difference and now, pedal kickback doesn't either. I tought I could BUY my speed instead of TRAINING for it...ughhhhhhh
  • 13 0
 Just got an ochain for my hardtail and now you're telling me it's useless?????
  • 3 0
 Actually. The conclusion of the article is that ochain devices do not produce an increase in performance due to reduced PK, But it will isolate the chain slap from the pedals, which holds true for hardtails as well as fs bikes. So this is good news for your ochain fitted HT.
  • 8 0
 biggest difference no chain makes imo is how much float your feet have since you don't have a hub to engage. makes moving about on the bike feel different and made me more conscious of weighting my feet.
  • 7 0
 Agree with all the conclusions here, but that still needs to be reconciled with all these people glowing about the amazingness of o-chain. Is is placebo? Presumably the EWS Pros are doing back to back timed runs and finding that it is indeed faster. Is this purely to improve pedaling through rough bits to eek out whatever speed possible?

Something else not mentioned here - what about pedaling while compressing? I have certainly felt this in instances where I am cornering right, so outside left foot down, suspension unloads out of the turn, then I am 'pedaling' back forwards to get my right foot forward as the bike compresses. It's a startling sensation feeling like I am getting bucked for half a second as the chain tensions up
  • 16 6
 they are probably getting paid...
  • 4 0
 When pedaling, O chain is like a normal rigid spider, as it chocks up against hard stops. It would have no effect in those situations, only when coasting with zero chain tension - which to point of the article, is not a major problem.
  • 13 1
 Great question! Is it the placebo effect or a real performance difference? I agree with Seb that pedal kickback as such is not a thing. The chain being pulled back during impacts by the cassette as it ratchets doesn't make any sense, as Seb outlined above- the wheels are simply moving too fast.

However, chain growth during suspension compression is still a thing, meaning that both the top and bottom of the chain need to get longer when the suspension extends. The chain is being tugged by the rear axle as its being compressed away from the cranks, but that motion is resisted by the spring in the derailleur and the clutch as the derailleur cage is forced to accommodate the chain growth. In that way, the derailleur acts as an additional spring and damper resisting the compression of the rear suspension. More chain growth (which is directly correlated to more anti-squat) creates more resistance to rear suspension action. I think that's why bikes with high anti-squat values ride rougher than bikes with super low anti-squat values. None of that, by the way, would be accurately described as "pedal kickback," because the cassette is freewheeling on the hub the whole time.
  • 4 1
 Ochain is located at the crank which means it will isolate the “chain slapping around wildly” from the crank arms. Aka you won’t feel the chain slap through your feet and the bike will feel more solid. In theory. Don’t know how noticeable it actually is and how much is placebo.
  • 8 1
 @jaydawg69: haha ochain does not have the budget to pay sam hill, loris vergier, neko mullaly, etc etc etc to all ride em. A lot chose to for the benefit they provide
  • 2 1
 @TEAM-ROBOT: i always thought you are on some sort of crusade vs. Pedalkickback and are missing some noticeable effects. I could not agree more with your recent post though.
  • 1 1
 @TEAM-ROBOT: big facts. Great explanation!
  • 5 6
 @optimumnotmaximum: Glad my explanation made sense. I think O-Chain is interesting and the effect of chain forces on suspension action is a topic that isn't quite settled. I guess I am on a mission against the term "pedal kickback" because it's such a misnomer and such a misunderstood phenomenon. For instance, you'll see lots of people in the comments of this article who still think that hub engagement and gearing affect how much pedal kickback they're feeling through their feet.
  • 1 1
 What they are feeling is similar to running a low engagement hub. Put an ochain on a low engagement hub and the bike feels super weird
  • 1 0
 @TEAM-ROBOT: This chimes with my experience of riding a single pivot (Orange - high anti-squat) bike with and without the chain.
Taking the chain off - it felt unexpectedly smooth and composed on tracks I was very familiar with. Not a placebo IMO because I wasn't anticipating any benefits (I had only removed the chain because the freehub was jamming on descents).
  • 4 1
 @TEAM-ROBOT:

True, but one thing I notice when I remove my chain is the rear has less support. Removing the chain (or somehow removing chain growth without affecting the axle path) definitely makes the suspension softer, but that's not the same as making it better. I think once you had compensated the spring and damping rates to achieve the same dynamic ride height, the difference in performance would be pretty subtle. (I could be wrong, as always).

I have ridden Ochain a bit and I do believe there is a benefit based on feel, perhaps because the feet are more isolated from chain-slap vibration, or the elastomers provide some damping to the chain movement - a bit like how clutch derailleurs make the bike "feel" smoother, even though they result in poorer suspension sensitivity in theory. More testing needed though.
  • 4 0
 @seb-stott: Great point- if the derailleur acts as a spring and damper, removing it would require adding additional spring and damper force elsewhere to compensate. No argument. But, the derailleur is a pretty inconsistent spring and damping force through rapid hits- its spring force is really only predictable and consistent on the first impact. After that, the derailleur's doing the Harlem shake through the bumps and it's anyone's guess on chain tension and derailleur cage position. So I agree that my suspension would probably be softer overall if I unbolted the derailleur and chain, but I also bet it's going to be more predictable and consistent.

And to be clear, I don't think anyone truly understands how these forces work on bicycles, how to optimize for them, etc. Mostly just designers and engineers feeling around in the dark and finding combinations of variables that seem to work in most settings. As with most stuff in the MTB sphere, there's been very little in the way of systematic testing to isolate variables and draw firm conclusions. Steve from Vorsprung seems to have a good handle on the efficiency losses from chain slap, and if he's right, maybe that's why clutch-equipped bikes feel faster. I don't know.

People talk as if Gwin losing his chain at Leogang definitely made him go faster, or perhaps it's even the reason he won the race. Are we so sure the chainless bike was the reason? I'm not convinced. He's won at Leogang A LOT, and he's had several 3+ second wins, so maybe it was just a good day for the Gwinner and the broken chain wasn't enough to cost him the win.
  • 11 3
 I have ochain on my DH and Enduro bikes and it just feels better in the rough, which makes me push harder and go faster as a result.
  • 22 13
 It’s called placebo effect
  • 6 0
 @creep-pea: maybe it's working to damp out all that chain flapping about and lets the suspension work ever so slightly better just to not have that mass freely moving around
  • 4 1
 @creep-pea: Nah, there will be a difference but it's not due to pedal kick-back. The undampened chain oscillating gives a noticeable feeling through the pedals. Not enough to make a real difference but still something you feel.
  • 1 0
 @creep-pea: I would normally agree with you but. Go do a couple of descents chainless and see.
  • 8 0
 A video to illustrate that was done by Vorsprungsuspension. It's on their youtube channel.
  • 2 0
 That was a great explanation. Didn't even know they had a channel, time to nerd out lol.
  • 3 0
 @DylanH93: it’s a rabbit hole. That dude is so interesting.
  • 9 1
 try running an ibis ripmo AF with an onyx hub and tell me the same thing Seb...
  • 1 0
 Agreed. I ditched Onyx for 36t DT on my DW bike, sooo much better.
  • 2 0
 @JohanG: I think I'm just going to switch my bike Wink It is the perfect excuse to use my 3 sets of onyx hubs.
  • 3 0
 The first time I ever really noticed kickback was on my Ripmo when I switched to Onyx hubs. Using the same hubs on a Stumpjumper EVO I have yet to feel any kickback.
  • 1 0
 There’s a reason why they spec the hubs that they do on a lot of their complete builds
  • 1 0
 @kokofosho: I sold my Onyx.
  • 6 3
 Strange to read this article and not see any mention of where in the cassette you are…most bikes will have significantly more pedal kick in lower climbing gears, and less as you get down into your higher descending gears. If anyone has played around on linkage design, you’ll see this, and can find where your specific bike will have the least.
As Steve at vorsprung pointed out, you’re feeling a lot of chain bounce compared to kick.

Now, one thing I’d like to see come up, is larger pulley cogs on high pivot bikes. Some new models won’t allow more with clearance, but some will allow larger cogs, such as the new Jekyll. A common complaint is power loss (drag) on high pivots using an idler. A larger cog on an idler equipped bike will generally decrease anti squat a little (not a huge deal since hp bikes have high anti squat by nature). So your climbing gears will still be very efficient. But you’ll get less pedal kick in some of the lower gears and you’ll have less power loss due to less chain angle (lots of articles discussing small cogs and loss of watts). Props to Turpen for running a 22t for this reason.
  • 1 0
 Good point
  • 2 0
 Isn't the small idler pulley the secret sauce for high pivot bikes? With a small idler, the point where the chain contacts the top of the pulley changes very little relative to the pivot point thus giving a consistent (usually small) chain growth through the travel. With a larger idler pulley that contact point moves to a much greater extent through the travel meaning that if you optimize instant chain growth/anti-squat at one point there will be more or less chain growth everywhere else in the travel.

Take a read of the Canfield suspension patent. They don't use high pivot or idlers, but they design the kinematics of their multi-link bikes so that the instant center moves with the chain top contact point through the travel. All reviews say it pedals through bumps like a dream.

Of course, I agree with you. As with everything bikes, there's always a compromise. Bigger sprockets are more efficient and longer lasting.
  • 1 0
 @zacjob: depends on where the idler is mounted. On the swing arm (I-track), near the “main pivot” or directly centered on the main pivot. Depends on how the designer feels like placing it to get kinematics they want. I personally like centered on the main pivot, as it requires less mounting points and hardware on the frame. While allowing some additional tuning with pulley size. For the most part, more hp bikes could be designed around larger pulleys than they are, and still get the same end result. Guessing a lot of designers are running into clearance issues and not wanting to design around the larger pulley.
  • 3 1
 Read again: There is mention of the small cog.
  • 2 0
 It seems like Seb didn't mention where you are in the cassette because he doesn't think pedal kickback occurs at any position in the cassette at a speed above walking pace. The wheel's just moving too fast for the cassette to engage, unless you're in your 10 tooth and do a drop to flat at 3 mph. There are other forces at play between chains and suspension, but pedal kickback isn't one of them.
  • 4 1
 A lot of bike “problems” only exist for marketing purposes. That bike you bought five seasons ago that was super fun, is still the same fun bike. But the marketing folks will have you believe otherwise. Vorsprung did a Tuesday Tune on pedal kick back. Basically what the article says here. It’s not an issue.
  • 3 0
 I raced a chainless downhill a few years ago and it feels significantly more plush without the chain. Whether or not it’s due to pedal kickback or some other factor I don’t know, but the suspension moves more freely without the chain.
  • 7 1
 Finally an article like this comes out.
  • 11 9
 pedal kick isn't so much a performance issue. it's a comfort issue. I have experienced it from minute(Firebird 27.5) to obscene(Megatower). it may not affect performance, but if you feel like the bike is trying to throw you off like a pissed off stallion, you aren't going to ride confidently.


this is why I worry/refuse to ride bike with noticeable pedal kick.
  • 11 0
 Yeah but didn't you read 'the science' above? HE SAID DON'T WORRY ABOUT IT.
  • 6 0
 Obviously an advertisement for big chain companies to sell more chains.
  • 5 0
 BiG ChAin is IN bed wiTh the NaNNy State tryINg to pUT uS all in cHAinZZ!!1!!
  • 2 0
 "the amount of pedal kickback a bike has is just a side-effect of how much anti-squat it's designed to have"

Partly. Kickback is more closely related to chain-growth than just anti-squat, if you had to pick just one. A good bit of anti-squat force comes from the acceleration of the rear wheel acting on the suspension and trying to extend it. This depends on the suspension design of course, but pretty sure this is part of dw-link's magic of having really good anti-squat without a ton of chain-growth or kick-back.
  • 3 0
 "Don't worry about kick back" My tin foil cap says this article is a paid for by SRAM and their shitty clutch springs that flog out every 6mths..... Kick back = spring dilapidation.
  • 2 0
 SO, i'm gonna tell a short story for all the OG's! 1999 NORBA Nationals. I'm young, and broke. riding a, modified for more travel, DBR. race day: loose my chain somewhere. Came in second place with over 40 entries......NO CHAIN. I truly believe that the bike was more active without a chain. BUT, I know i was faster because of my "SCREW IT, DONT USE THE BRAKES" ATTITUDE.
  • 4 0
 Axle path on a Specialized Demo. Didn't the Pinkbike comment section have a dedicated expert on that subject?
  • 3 0
 RIP Protour
  • 6 1
 Ever notice how much longer a wheel keeps spinning without a chain?
  • 2 0
 thats a given due to less drag in the freehub. again, anther similar thing to running a low engagement hub.
  • 1 0
 I wonder why I never see this mentioned in the discussions about chainless runs. Endless discussions about how it affects suspension, or that it reminds te rider to keep good speed and even placebo effects get thrown in there.
  • 1 0
 @mtbtrekracer: eh? Similar to running a low engagement hub? Please explain.
  • 2 0
 @NZRalphy: less friction and "grab points" i have two exactly the same hubs except one is low engagement and other is 102t, the low spins for longer and has a "free'er" feeling IMO
  • 4 0
 Im probably wrong, but being a flats only rider, i find high kickback bikes really buzz grip away from under your feet.
  • 1 0
 How a bike feels comes down to a lot of things, so its hard to tell what makes a bike have less grip or feel harsh, but i am suspecting a similar thing. For me high antisquat ( high kickback) bikes feel a bit harsh. I recently moved from a bike with very little antisquat to a bike with extreme amounts of as. The new bike feels a lot more energetic but also harsher with less grip ( even after switching shocks springs etc. ).
  • 1 0
 "the derailleur's clutch might impede the suspension movement (very) slightly"

Ha! If pedal kick-back from top of the chain tension is basically moot according to this, the clutch is even more negligible. As you said, the chain is flopping around and not taut so not much force is going through it. Even if it were taut, the force to move the cage on, for example, a Shimano 12-speed clutch, is less than 10kg at the end of the cage. So if 60+ kg through the floppy top of the chain is nothing to worry about, 10kg through the floppier bottom of the chain is definitely nothing to worry about.
  • 2 0
 I started using the O-chain last month. I don't know if it has made me faster, but it feels bottomless. I ride a 130mm trail bike, but after installing the O-chain, I feel like I'm riding a 170mm enduro bike.
  • 4 0
 Glad this fella finally cracked the code. Now we can go back high pivot bikes with no idlers. What a relief.
  • 1 0
 Similar to the huck to flat slow-mo test could we create a rumble pad to test the bikes at speed while filming slow-mo??? Would be interesting to see how different shocks and different suspension kinematics are able to control oscillation over varying square/round bumps at speed or under braking... @seb-stott
  • 1 0
 All I know is my Intense Carbine has some serious lack of suspension when I'm riding really steep trails and barely holding on to traction under braking. I would buy another bike just to alleviate the awful braking forces I experience....
  • 1 0
 I’ve got a single pivot, Onyx hub and run flat pedals - I ought to be having all sorts of pedal kickback issues given some of the feedback up there but I don’t feel anything different to running a low engagement Hope hub.

I agree with Seb, it’s all in people’s heads. Buy that Ochain placebo if you buy into it but it’s not really doing anything except adding a load of slack into your initial pedal pickup and I thought we all agreed that was bad . . . didn’t we?

I’m off to watch the Vorsprung video.
  • 4 0
 So….just ride faster and none of this is an issue?
  • 4 0
 BUT AARON GWIN WON WITHOUT A CHAIN
  • 5 0
 = the chain is the only thing stopping me from winning too!
  • 1 0
 My old kona bass used to fly out of berms using the pedal kick back under compression trick. My mates ddg slammer did it aswell. it was a bonus feature once you get used to it.
  • 2 2
 One advantage of pedal kickback that is not mentioned is pumping. With pedal kickback, if you keep your pedals level, as the suspension goes through the travel, it pulls the chain and subtly rotates the cassette. With pedal kickback, you can start from a dead stop, get on the bike and start pumping. The bike will move forward. Pedal kickback develops speed when pumping the bike.
  • 3 0
 From zero to a fraction more than zero mph, sure. But after this your wheel out-rotates the rate of chain growth.
  • 2 0
 I wasn't even aware that I should worry about that. Maybe I just don't watch enough industry advertisements to know all the things I should be worried about.
  • 4 0
 I've secretly fitted placebos to all my bikes and I'm so much faster now.
  • 1 0
 You could have just posted Steve from Vorsprungs highly detailed video.

is it a thing? well if you have a single pivot bike on flat pedals it most definitely is, should you worry about it.... probably not.
  • 1 0
 I always thought a pivot concentric with the BB would be the holy grail and i bought a Cove G-spot in 99 that i thought would be the future of suspension, and for the most part, it was.
  • 2 0
 Awesome as always, thank you. Loving the "reasons not to buy new stuff" series you've got going
  • 2 0
 I still think suspension can work better without a chain even if only due to the reduced unsprung weight.
  • 3 0
 No kickback from OChain for PB.
  • 3 0
 Chainless XCO is where the industry needs to go.
  • 1 0
 Good article mate. Nice and to-the-point. Pedal kickback or not, sure sounds like there are some merits to riding down hills without pedaling Smile
  • 3 4
 This completely ignores what happens when you’re holding the the rear brake. The cassette will rotate forward until it engages, and then the cranks will come back, or the rear suspension will stop moving. It absolutely hurts bike performance*

Single pivots with neutral main pivots won’t really experience this at all, as the cassette will follow the caliper as suspension compresses, for example.
  • 2 0
 I just want to know where that Gwin guy went, does he still race? He looked pretty fast.
  • 4 1
 He found Jesus and they're into marketing now.
  • 3 0
 I don’t care what your fancy science says. I need an O-chain.
  • 1 0
 silence makes my bike faster (read: me) than almost anything....because i am a little flower who doesnt want to trash his bike even though it is MORE than capable LOL
  • 1 0
 My Canfield Jedi without a chain, cassette or rear mech works like a dream in chunky terrain. Ride this setup several weeks every summer.
  • 1 0
 "After crossing the line, he could be heard saying "The suspension works so much better without a chain.""

Also Troy Brosnan could be heard saying "you mother f*cker"
  • 2 0
 kickback was never noticeable until I got new hubs with higher engagement
  • 1 1
 Which is why zerode bikes make what they make, Canfield Jedi and the Canfield CBF suspension which has little pedal feed back on suspension that’s why they are fastest
  • 1 0
 Wat? What does zerode have to do with CBF?
  • 1 1
 Cheapest way to eliminate kickback... add a couple links an switch off the clutch..
Funnest way to eliminate kickback.. Go SS \M/
  • 1 0
 I mean, I never knew I had to worry aboot kickback until PB xommenters told me I should worry aboot kickback.....¿
  • 1 0
 There is no such thing like pedalkickback? Ok tell the guys who rode the 2000s Sunn Radical.
  • 2 0
 Lack of free hub DRAG helps those chainless riders
  • 1 0
 Try riding a mondraker summum with 300% antisquat at top out....
  • 1 1
 Pedal kickback is just an excuse people use if they get beaten by their mates. Just go ride your fkn bike!
  • 2 5
 Just a theory. When there is no chain . There is no chain tension compressing the shock back in. Platform as it's called . Also called anti squat?
I believe this is why the suspension works better with out a chain. The chain can not influence the action of the shock.
Tells me more about the value or the lack of value of having platform. Which bike reviews love as it helps with climbing. Apparently. It does at the expense of the DH ride. Which is what I love . The climb . Whatever . I ride slow and steady.
Want a plush DH experience. Get a frame with low anti squat numbers.
  • 1 0
 The Specialized should come with a bash guard and ankle braces
  • 1 0
 So long as it’s not a URT it’s gonna be just fine.
  • 2 0
 now those were the days, I had a 1997 barracuda XXXC that felt like there was small bombs connected to the pedals!
  • 1 0
 URTs have the same pedal kickback as a hardtail, which is _none_.

The BB moving (rearward) is not pedal kickback.
  • 1 0
 Looks like orange will make a comeback!
Pedal feedback and no idler…
  • 1 0
 Yep, my 222 had massive kickback, ended up building that frame up as an enduro style rig, loved the acceleration and jump on the pedals in a hole and it'ld kick you forward.

People saying kickback like its a bad thing, you can just lock out your crank and bounce along the trail Smile
  • 1 0
 With this said bring back the old design of the LTS





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