Wishing all those magazines out there like pink bike would do analysis like the ones you do. Start your own bike review website!!

That's some serious math :)

After breaking my chain at a bike park a few weeks ago and running chain less for 1/2 the day, I now pay way more attention to pedal kickback. I didn't realize how much the kickback actually effects riding when doing downhill, especially in slower more technical descents, where low speeds with big hits are the name of the game.

Love it, best explanation I've seen!

Man, that is some in depth analysis. Thanks for the hours of work you put into that.

Killer video ! Thank you for your time and effort in creating this high quality content!

Rear hub POE should be included in determining an acceptable amount of pedal kickback as well.

Excellent analysis with super visuals. I’ve only ever experienced kickback on the Capra in steep, relatively slow big hit settings a- which matches your analysis of when it would be the most aggravated. I found it very noticeable and felt the suspension lock up appreciably under these conditions.

Great work, again. Gonna have to watch a few more times to truly understand that and also go back and find mechanical of machinery book ;)

I love that your so informative on this stuff and thats why I subscribed thank u!

You changed my mind. I've been listening to reviews mention kickback and I've thought about how it works. I thought it wouldn't matter if you're moving but nobody goes into detail like you did. Very interesting.

Now i understand why specialized put low engagement hubs on the enduro

One really interesting note is that when doing the "worst case scenario" analysis, we discussed the required forward wheel motion in a 25 tooth cog. That said, I think it's much more typical that most folks are using their smallest cog (10-11 tooth) for most descending. I am not even the strongest of riders, but even on "blue" trails, I am descending almost entirely in my smallest cog. This would have a significant impact on pedal kickback and the wheel speed required to eliminate the issue, yes? However, as the owner of the Enduro mentioned in this video, this analysis helps to explain why the bike actually feels calmer and more easy to ride on days when I am really cruising! Interestingly, on days where I am decidedly trying to ease off an take things slower, the bike itself can feel more tiresome to ride - likely due to the increased force transmitted into my feet from the slower wheel speed.

Great video, I appreciate the work. I happen to own this bike and I can tell you firsthand it did have some pedal kick back until I upgraded the hub and now I feel nothing. It has the best grip of any bike I’ve ever ridden, super efficient and feels like a cloud.

Gonna have to rewatch this a few times... so much maths and science... but love it and your channel!

can you make a video about the specialized stumpjumper?

Yes I do feel the pedal kickback on my nomad v4 while pedaling. I use flat pedals and pedal kickback can be annoying. The more alive the suspension is the more pedal kickback it has. More sag, less pedal kickback. The size of the chainring has an noticable effect to the pedal kickback. Smaller chainring, more pedal kickback. These are things that I've noticed while riding. I feel that. I'm not an engineer. Interesting to see the theory and what it means practically. I want to mention the marks on the freehub that are caused by the cassette. I believe they come from the pedal kickback in certain situations. Slow drop for example. Gear matters, too... you talked about all that stuff. Yeah, I know the feeling when a bike jumps forward with the movement of the suspension. My old votec v8 was like that, 165mm travel. Disadvantage was a massive pedalkickback while pedaling and also the suspension stiffend up while breaking. Felt almost like a hardtail while breaking.

You know, I think you just made me a better technical uphill rider. Not only does hitting a step with your rear wheel slow you on the obvious way, it causes Pedal Kickback. I already wondered why it sometimes feels harsher than it seems it aught to. The next level realization though, is that you can also use the rear suspension to assist you over that same step, by preloading for lift, and using the kickback for boost prior to the step. Gives me some ideas to play with

Hey man, great analysis as usual! I actually wanted to do this exact thing but never got around to it. Factoring in speed and hub speed is important in calculating pedal kickback. Quick follow on question, what software do you use for you animation? I've never seen anything that good for depicting bike suspension movement!

Great work, your videos are very interesting to watch. I had wondered about wheel speed as well but this proves it, pedal kickback will happen regardless of wheel speed. Now to do some tests and see if I can feel it.

Great video, very interesting topic.

I definitely expanded my understanding on this thanks to your insight. Would love to experience a long travel bike that pedals up climbs with all these quirks minimized. Long travel Forbidden?

That was a great analysis of PK!

That is exactly, I looked for! Professional, perfect job!

On my old Diamondback Release I noticed a fair amount of kickback in big lower speed drops, which I did a lot of on that bike It never felt good choppy fast rough terrain, but pumped very well and felt fast on flow trails.

Phenomenal analysis that incorporates the kinematics of the rider! So during descents, if your rear wheel is rotating fast enough there’s no chance of experiencing pedal kickback. It would be interesting to make an Excel spreadsheet of the max size drop you can hit at a certain velocity and gear combination 😎 (though to be honest the emoticon should be 🤓 )

Amazing Video!!! I was wondering if you have any sugesstions for good literature to write an scientific work about the physiks of the rear suspension of mountainbikes. Thanks

I experienced pedal Kickback for the first time this morning on a slowish speed 6-7 foot drop and I can honestly say your analysis confirms that pedal Kickback is probably what I felt. I was not going fast enough to counteract the pedal Kickback and the drop was even bigger than your example. I'm not sure what the pedal Kickback on the Privateer 161 would be but I swear my pedals kicked back almost 90°.

Fantastic video and I understand this so much more now. What software do you use for the computer voice over?

Super interesting. One thing I found is that trails we ride changed along with the bikes: due to the groomed trails in bikeparks getting the norm, the drops and jumps are happening with a lot more flow and speed, hence maybe less sense of kickback when riding for the majority of people? When the rooty, twisty steep trails in the woods were the norm, I had a bike with a lot of kick back and found it really unpleasant.

I don't think that I've ever experienced pedal kickback while riding. If I have then its effect was, for me, in the noise considering the total trail feedback. As a practical matter, since the wheel is rotating in the direction of travel it seems like the would be minimal "like a short pedal stroke without pedaling" as was mentioned in the analysis. Great job by the way. Your explanations do help me understand the effects of suspension that I do feel such as the anti-squat. Thx.

Great video, keep them coming! One quick nitpick about the 1.5m drop example. It seems like in your 1.5m drop, you assumed the suspension didn't slow down the rider at all. I'm sure you're aware of this, but it actually makes the speed needed to not experience pedal kickback significantly lower as it will actually take longer than 26ms for the rider to bottom out the suspension. Without the rider weight and spring force (not to mention air springs and bike geometries are non-linear) it is hard to estimate the actual time it would take from contact to bottom out. Assuming a perfectly linear suspension, a 70kg rider set up at 25% sag means the suspension's effective spring constant is about 18000 N/m, and the spring absorbs around 200J of kinetic energy before bottoming out. That same 70kg rider moving downward at 5.4m/s has about 1000J of downward kinetic energy at the point of contact. Without getting into the integration needed to actually calculate the bottom-out time, I would give a thumb-in-the-wind estimate that it would actually take more like 30-33ms for the suspension to fully bottom out, which would result in something more like 15-16 mph.

Best part of vid at 2:55 sweeet!

Hi. Nice video. I like the video but I would see one point different: you say that moving forward means reducing the noticeable amount of kickback (pedal kickback-wheel rotation*cog ratio). I think that is only true for flat drops without speed and roll over square edges or drop with speed. But if you have to pedal and put the chain under tension it will still give you a pretty unround feel in your knees. I for instance sold my beloved Orbea Rallon 2017 because it had a slightly high pivot with high anti squat and was giving odd knee feeling on technical pedal sections. After increasing front chain ring from 32 to 34 it got significantly better but I still sold it for the reason of too high kickback. My new thunderbolt is ways better regarding that point and does not let me feel any bad feeling in the knees and is ways more active under pedaling. Despite that the Rallon was a good Enduro Bike as it was amazing on non tech uphills.

Love the suspension videos. Any chance of making one for the specialized stumpjumper/turbo levo suspension?

Very interesting video. I just purchased a 2022 Specialized Enduro Comp with stock wheels. I believe the hub is only worth about 18 PoE? Was planning to switch them wheels to something with a Hope Pro 5 or I9. But, after watching this video, it made me think twice. That being said, my home trails have a lot of technical sections to climb and bomb down. I am now concerned that if i were to get wheels with high engagement hubs, the climbing and descending experience could feel worse potentially? Especially when there is a need to climb tight sections with roots or rocks at slow speeds. What are your thoughts?

If watch the vorsprung video on this topic you can see a real world example of the 36 degree scenario, you just drop a bike on flat ground and watch the cranks move back a very large amount, however you can simulate a more realistic scenario quite easily, take a decent amount of pressure out of your rear shock (enough so you can almost bottom it out with slightly more than bodyweight) and then ride along at moderate speed, jump up off the pedals and move you feet out of the cranks to then slam down your weight through the seat to compress the suspension, you will notice far less kickback due to the bike moving. I haven't tested this with different engagement hubs, but you could simulate the difference between a high engagement and low engagement hub. Out of interest, would the "neutral" gear that some DH racers install on their cassette completely negate kickback? They have a blank gear in the middle with no cogs so the chain can just slide back and forward.

man this is awesome thanks!

Thank you TrailPOV!😊 I have a tricky question for you: Lets say I have a special rear hub freecoaster that, whenever Im coasting it automatically shifts the driver (pawls) out of any contact with the ratchet ring of the hub. Will this special hub eliminate pedal kickback?

If you add an idler pulley/wheel to the 2020 specialized enduro where would be the best location to put it? Would it help reduce pedal kickback? I have a 2020 Enduro and am thinking of trying to make one that mounts off the bash/chain guide mounts. Good idea or bad idea? Would be curious to hear your thoughts. Awesome videos.

Great analysis, we should use smaal teeth when descend at trail, applies any fullsus bike

Nice video! How many hours you put on these animations? eheh. Yes, exactly! Kickback is only relevant mostly during bumpy climbings (not only kickbackº is higher on climbing gears (i.e small front chainring and large rear cogs) but also, at slow speeds and when the chain is under tension the freehub/cassette does not freely rotate forward to accommodate the chain extension). On downhills, the kickback is not very important IMO. Not only the kickbackº is much lower on descent gears but also, as you said, at faster speeds the cassette rotates forward allowing the chain to freely extend. Cheers

Do a review on popular rear suspension designs with positive and negative features. And what type of rider would benefit from said designs.

This must have taken 100+ hours to edit. Awesome explanation!

It would be interesting to see the correlation between paddle kickback and emtb motor torque sensing... At least it would up the average speed uphill, so it would help with kickback on uphill technical trails...

Hi, great video! I really enjoy your suspension analysis videos! Would you mind sharing what program you are using to simulate the linkage and linkage motion? I'd like to be able to analyze a variety of bikes to educate my next bike purchase, and as an engineer, I really enjoy technical analysis of the designs for its own sake (don't worry, you won't see me stealing your videos). Thanks!

Hey there, How does the amount of suspension generally impact the amount of pedal kickback? Would a high engagement hub for example make pedal kickback on a long travel enduro bike be more/less noticeable than on a 100mm XC bike? Is there a way for one to calculate the contents of the video at home without buying software? Is there a way to get a rough idea of how much pedal kick a bike has in a scenario where a brand doesn’t publish the information online or in a manual? Thanks

These numbers are great. Say you're hucking to flat again - would the suspension behave differently if during the jump: (1) you let your wheels spin; (2) you lock up your wheels; (3) you continue pedalling sam blenksinsop style?

So when you are pumping, you hold the cranks in place, which means that the growing distance between bb and rear axle increases the chain tension pulling the cassette forwards. That makes high-engagement hubs like DT Swiss ratchet actually accelerate the bike a little bit :O

So by using the smallest rear sprocket during downhill, the wrap angle would actually partly compensate the chain stretch?

How about jamis hardline/portal 3vo suspension? It looks pretty nice

Does switch infinity actually reduce pedal kick back on yeti sb165? Do you have any info on that? Thanks.

For the last question does it matter or do you feel it. I for one don't huck to flat doing mach 5 so my ass moves down but I push the bike forward to get a lower COG. When that happens I don't notice 10 degrees of pedal kickback because my legs are a fixed length and if I move down and back my stance moves accordingly.

Thanks for the video but i still have two questions, First i want to buy the 2021 Propain Hugene and looking at it it is very similar two the Pivot Trail 429 (?).The Pivot is a Virtual Pivot Point bike and as far as I know should have very small Pedal kickback because of the extra hinge. Did I understand that right? And second is the Propain Hugene even a VPP bike because if i search it up,one website says the bike has a VPP suspension design and one says it looks like one. On the official Propain site there is nothing mentioned about the VPP only about the links.

Excellent analysis, seems like pedal kickback won't really have a big impact on a riding experience. I never realized that you could pump a full suspension bike on the flat

What if link pivot is located at Same position with bottom bracket? Does that remove pedal kickback?

I see the pedal kickback as a main force preventing wasting energy on climbs. But too much and the suspension will not get out of the way for the hit. I figure this is why the likes of Santa Cruz and ibis etc, want to use two linkages. To try and get chaingrowth at the start of the travel, but then minimise it towards the end? This is what I have taken from watching many of your videos. I hope I have understood correctly. 👍

I noticed loud sound when I drop the rear of the bike, its clearly my free hub engages, DT swiss 350 ratchet 24T. 180mm travel coil shock. Im notice it when riding as well, any solution? Thinking to add more grease to the freehub body...

Do you have any plans to do one of these on the Devinci Spartan 29?

Does anybody ask regarding the fork offset pros and cons between 44mm and 51mm offset ?

@10:20 how does the lock-out impact this? I would think it lessens the kickback.

Doesn't kickback get worse in your climbing gears? Why would you be descending in the top of your cassette? I went to the garage and cycled my trance through it's travel in both ends of the cassette. In the top I can get the bike to backpedal a little. In the bottom of the cassette I couldn't get the pedals to move any noticeable amount. I am running a DT350 with the 54T upgrade. The reason I am wondering is I am building a new bike and am about to pull the trigger on a set of i9 wheels with the hydra hubs.

Loving this nerdy madness !!! yeah !

Interesting... I know there are some scientific thesis on pedal kickback and so called threshold speed on research gate, but i didn't manage to get access to it. Looks like if you're an amateur, riding slower and with faster damping setup(softer), using more travel you are more affected. That would mean bikes like commencal supreme dh 29 make sense not only for guys like Amaury Pierron. Finally i've found an excuse to buy one 😀

Is it conceivable that a set of conditions exists (suspension configuration, drop size, forward velocity, rider weight, etc.) where it would become very likely that a chain breaks due to kickback forces?

I understand pedal kickback now. Thanks for that. I don't know whether I've experienced it though. How would this feel?

I have hardtail, why am i eaven watching this :DD

Thank you for the explanation. So, there are so many videos of pro's going up stairs in their bikes, it gets harder because that's when you will experience more pedal kickback?...

Is it possible that my bike has 0% pedal kickback or does every bike has it because when i let the air out of the shock and pump it through its travel the cranks dont move (cube stereo 140)

You should do the giant suspension

Some downhill bikes would be awesome! Keep up the good work

wait im confused according to the math when descending, being in certain gears effects your suspension feel due to the tension on the chain?

I didn't think pedal kickback was a thing, until the day I broke my chain riding my local trail. It was all down hill from where it happened so I rode down with the chain off and my bike felt like a cloud! Now I am anxious to find a way to achieve that feel... I might try that new chainring that is supposed to eliminate pedal kickback!

Can you make a video on Jamis's 3VO suspension?

Nope not really, some wallow seems to stiffen the pedal but if the suspension is set right however I do worry kick back can accelerate an over the bars casing face plant scenario. Generally on a downhill where it matters no not at all

So that's why my bike has the pedals rotate backwards if I stop and get off right after landing. It's weird , makes the chain come off the big chainring towards the smaller one.

All very interesting but tell me if I'm wrong but a Emtb can't get kickback because of the sprag bearing. Another reason why E=Mtb²

Can you do a review of the new GT Force ?

For the same bike, can you tell what will be the impact of the chainring changing size? I heard somewhere that it will be less kick back if the chainring is bigger but it make no sense to me.

Funny moment: when you decide to install better wheelset/rear hub with 3-5 degrees ratchet engagement - you can make your pedal kickback more notable)

Actualy i now realize that this maybe is the reason why enduro climbe that well. In the beginning of the video you say that enduro have the biggest pedal kickback and a lot of reviews say that enduro is very good climber . If you don't understand, when you pedalling to the hill the suspension should be less active because the chain can't go backwards when you are pedallin forward. That can allso cause some kind of energy lost because you need to give extra energy to keep the suspension inactive but that is probably less then pumping the shock all the time . Worth mentioning in the video.

i dont understand 1;04 why does wheel rotate backward?

The Scott ransom has some good amount of kickback

Recently read an interesting article from DT Swiss in the negative effects of increasing hub points of engagement on pedal kickback. It would be awesome if you could explain this inverse relationship! Thoughts?

How could a device like o-chain, that reduces kick back, affect the reasoning?

So the specialized enduro could really benefit from the Ochain then ?

Wow, thank you for finally putting math to what I noticed back in 2011, when I got rid of my Specialized FSR. I had a major problem climbing sustained, rocky climbs. Flat trails were never a problem and I think the bike descended pretty well too. Although, I do have a ton of scars on my lead shin, I wonder if this is from that pedal being forced up when taking big hits, hmmm... I noticed that when I would "bump" up a rock, water-bar, etc... that it would be MUCH harder to pedal on that current stroke, ultimately stopping me in my tracks. I found out about chain growth and pedal kickback after reading a bunch and figure this was the reason why. Anyways, I tested a bunch of bikes and I remedied this by, well, buying a Trek Remedy. I would love to see your analysis of Trek's ABP or DW's Split Pivot design (found on Devinci bikes and others?) to see how they stack up climbing and descending. Thank you for putting together these technical videos, every other video out there is VERY anecdotal.

how do you make these bike analysis? wich software do you use?

Hey, can you review any trail bikes from polygon?

Why does wheel rotation decrease PK? The chain is still pulling isn't it?

The old gt fury 2014-2018 suspension design almost avoided this issue entirely.

Just for understanding: is anti squat pedal kickback on purpose to firm up the suspension when pedaling???

Wow!

Hi Matt, as you let us understand you are havingna lot of demand for producing bike analysis, i am proposing myself to help you. I know how to use linkage and do analysis, let's discuss what i can do for your channel

Just watched the video, I now need a drink!

never heard of it until i experienced brake jack and pedal kickback at the same time. i was like"where did the bike go?"

To be honest I think I've never felt pedal kickback in real world scenarios, but my bike is a full suspension XC bike with 100mm front and back. Considering pedal kickback could be unnoticeable on an Enduro bike under some situations which has almost double travel and the suspensions tend to dive naturally because the long travel, ¿is it even possible to feel pedal kickback in short travel bikes, up to maybe 130mm travel? As I said I've never felt it in real work scenarios, and the frame has a lot less travel, which decreases the angle that could cause it to be noticeable, and all the bells and whistles about it in such bikes would be more of a gimmick.

I've always ride hard tails

What about specialized demo ? Is it the same ?

You've assumed the rider has fixed joints? I would assume that in most real world scenarios, unless a rider has a particularly stiff ankle (and knees/hips), they won't actually feel much of this. In a healthy joint there will be 20-25deg of movement to buffer any small kickback.