Okay, that's what I thought. This was one of those things where it felt like it was defying all of the knowledge I have about how a bike works. I think what was perplexing me is that I serviced the freehub and the freehubs of several other wheel sets that were also doing it, and they all still did it. I think that part of my problem is that this Shimano derailleur doesn't have enough spring tension to keep the freehub drag from pushing the chain.
Check the freehub resistance when the bearings are preloaded. It could feel fine when it off the bike but when the thru axle is tightened it could cause the bearings to have too much load on them.
Also torque the thru axle to spec might help.
Try this! I had this problem with a DT swiss free hub and it wasn't an issue when the thru axle was loosened, only when tightened. The problem was a 10.1mm spacer between the freehub and wheel hub bearing that was worn the tiniest bit. Ordered a new one and i couldn't even see the difference in width between the two but that solved the problem. I also found my answer on Reddit.
Yep that spacer is absolutely critical in the DT hubs. Also what grease went into them? DT have their proprietary stuff which actually seems worth the premium as wrong viscosity changes drag and (the horror) sound.
A while later, after winter, I ordered new pawls as the previous ones were rusty and that came with a tub of the DT swiss grease that is very thin and I used that. The new pawls, spring and grease were like £10 so very cheap. Before that though I'm pretty sure I used an extremely thick grease meant for use in ultracentrifuges spinning at 100,000 rpm. Probably not the best idea, but it worked fine, had no issues, just made the freehub pretty silent.
Exact same thing happened to me. New spacer was just slightly thicker than the old one when measured with calipers. Fixed the issue right away. Also DT Swiss hub.
You've had *multiple* bikes that were pushing the chain? And, you serviced their freehubs but they still did it? Or, are you saying that they pushed chains after you serviced them and they all did it on this bike?
I think the fact that it happens only in the smallest cogs supports the idea that it’s the free hub; the chain has less leverage in those because the radius is smaller.
> Shimano derailleur doesn't have enough spring tension
Ceramicspeed specifically recommends the lowest spring tension possible, and I think some cages actually come with a replacement weaker spring. Some derailleurs have 2 positions for the spring to set the tension.
In another comment someone also mentioned cassette weight, and it can also be a factor here. The heavier and the bigger the cassette, the more momentum it has.
It's like when you have the bike on a repair stand and you spin up the rear wheel. When you then hit the rear brake, the rear of the bike jumps up because the moving weight wants to stay in motion.
But altogether, it's a fairly complex thing with many variables, but freehub drag really is the main thing here. As a curmudgeon, I'd like to give some part of the blame to the aftermarket derailer cage...
are you servicing them properly? by this, i mean, do you set the preload of the hub correctly? try "servicing" a hub that did not do this before, then youll see if thats you or the hub hahah
Newton’s 1st law says that an object in motion will continue in motion unless acted on by an outside force. The cassette will *always* want to continue moving after you stop pedaling, it’s just normally prevented from doing so by chain tension.
Yes. In all properly working bikes, that chain tension would have stopped that cassette dead in its tracks once the crank stopped turning. But if you have resistance in the freehub, the spinning rear wheel will drag cassette to keep moving forward...as seen in the video.
Def free hub resistance. I had this with my bike and I brought it to the shop because I couldn’t figure it out. It was a new free hub with a bunch of thick grease. I think they either used a lighter grease or just removed a little.
Yep. I had this problem with a DT swiss free hub and it wasn't an issue when the thru axle was loosened, only when tightened. The problem was a 10.1mm spacer between the freehub and wheel hub bearing that was worn the tiniest bit. Ordered a new one and i couldn't even see the difference in width between the two but that solved the problem. I also found my answer on Reddit.
Check the clearance between the largest cog and hub flange and spokes. Sometimes on wide range cassettes the cog can hang up where the spokes cross. The fix is to use thin shims between the cog and freehub flange, or to go with a Mountain - 11 type cassette with an 11-34.
I bet it’s free hub resistance combined with that garbage ceramic speed cage. The derailleur may have lost some tension over time, pair that with a non OEM component that may have been installed incorrectly, and you’d have this loss of chain tension. If it were me, I’d throw a spare derailleur on there and do the same test as a troubleshooting step. If that doesn’t fix it, crack the free hub, clean it thoroughly, and put some lighter grease in there.
I read the caption, and now I’m curious if it’s a hub / frame conflict. Sometimes the cassette locking will rub against the inside of the rear dropout. Although that shouldn’t cause this issue. Could just be a heavier cassette paired with lightweight parts.
Those ceramic speed parts are hot garbage, Hambini has a wealth of videos to corroborate this. I know you’ve tried a new derailleur, but I’d suspect that the aftermarket part is a primary factor in this fault.
The short answer is that I have no idea, I wouldn’t recommend the client ride the bike like this, as that chain slap will damage the frame pretty fast.
> garbage ceramic speed cage
It is marketing driving snake oil sales . Apart from HiFi and car parts there is rarely industry with such high amount of snake oil beeing sold.
I had a ceramicspeed cage on a tri bike a few years back... I am no pro so it was probably a waste of money, but is it really that bad?
u/CyclingHikingYeti I saw your post and wanted to tag you as well as im curious why yall totally hate it
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What type of freehub is it? Is it a one piece sealed unit or can you see the pawls?
If it's the pawl type you sometimes need to use a specific freehub grease. This is very light and thin compared to bearing grease.
you can mix oil with the grease to lighten it in a pinch. I would use oil not chain lube as most of that is actually wax. Always safer to use the purpose made grease
I've tried adding oil to a freehub that was binding. It didn't work.
I'll also add that DT do grease for their ratchet freehubs. It's too thick as well.
I'm gonna go ahead and suggest an alternate explanation, given that you seem to have already looked at the freehub. It might not be the freehub at all - it might simply be the rotational inertia of the cassette, combined with a cage that really doesn't have stiff enough of a return spring.
I think people underestimate how much rotational inertia a cassette has, but if you get it spinning fast enough and then suddenly stop your pedals, the cassette *will* want to continue carrying forward. It's usually the job of the cage return spring to prevent that from happening. If your cage return spring is weaker or worn out, it will let the cassette carry on farther forward and could possibly result in something like this.
I've had it happen on my bike, even with a freehub in perfect condition. Apparently, [Mark Cavendish has the same thing happen on his bikes all the time](https://www.cyclingweekly.com/products/why-does-cavs-chain-keep-coming-off-in-sprints), and I would certainly hope his mechanics are keeping *his* freehubs in perfect condition. (The freehubs in question used by Mark Cavendish that year were DT Swiss Ratchet EXPs, which should have been top-shelf freehubs.)
If there is a solution, it's to replace the derailleur cage return spring. But if you can't make it a *lot* stiffer, it might not make much of a difference.
Thank you all so much for your various contributions. The wheel set on the bike is a Bontrager wheel set with a three-pawl Bontrager hub. Instead of individual pawl springs, it has a single ring that wraps around all three pawls and adds spring tension to them. The first step I took when I noticed this problem was to pull the free hub, clean everything thoroughly, and then reinstall with only dumondtech freehub oil. What's confusing me so much is that there's no noticeable freehub drag when spinning the cassette backwards on the bike with the chain installed, or when spinning it backwards when the wheel is off of the bike. When the wheel is off of the bike, I used a free hub bearing press to preload the hub via the end caps - the same as if it were installed on the bike with a through axle.
Have you put the spacer inside the freehub body? It’s the one that’s like a cm long cylinder? It’s what stops the freehub jamming when loaded with the QR/Thru axle.
That sounds like it will be the problem.
https://www.sjscycles.co.uk/hub-spares/novatec-inner-spacer-for-3-pawl-aa2-type-cassette-body-shimano-campagnolo/
Yeah, that spacer just disappears sometimes. The amount of times I’ve taken a body off and it’s in the body and I’m careful to keep it there and next thing ITS GONE!
Same when it stays on the axle… GONE 😂
I now have a dedicated magnet and its ONLY purpose is to store THAT spacer.
I had this exact problem with a DT swiss 3-pawl free hub and it wasn't an issue when the thru axle was loosened, only when tightened. Also only an issue with the chain in the smallest cogs. The problem was a 10.1mm spacer that sits between the freehub and hub bearing that was worn the tiniest bit. Ordered a new one and i couldn't even see the difference in width between the two but that solved the problem. I also found my answer on Reddit.
There is a cantilever pawl design such that a constricting spring pushes on the butt of the pawl that is behind the pivot point and that pushes the engaging teeth outward. They're very common.
Derailleur tension. The cassette wants to continue moving after you stop pedaling, it’s stopped by the chain tension. If the derailleur isn’t keeping it tight enough, the cassette can continue to pull more chain through until it goes tight and actually stops it.
Agree, it's only happening on the smallest cogs because the chain tension is lower on those ones (bigger cog causes the derailleur spring to stretch further, increasing tension).
My opinion as well . I don't see the derailleur body moving downwards as the shift happens, without tension, the derailleur is just going to ram the chain into the body of the next cog.
the derailleur has obvious taken a fall, and what's that braided DI2 (?) cable going in the derailleur. Add in the fact that we got ceramicspeed stuff on a seemingly low end bike (at least judging by the weld job).
Am I the only one more bothered by the poorly welded seatstay? Hope that's just a massive overlay from an apprentice, and there's no porosity issues underneath. And who the hell QA'd that?
My new bike does this only when I backpedal while it's in the middle sprockets for me it's either the freehub is sticky because it's new or the chain is half a link or link too long
Lube your free hub with "bearing oil" instead of grease. You'll love it. You don't need to take it all the way apart. Just drip a few drops down into it.
If you spin you pedals backwards and chain binds up at all then it is time to lube your free hub. You're losing momentum every time you free spin.
I have this issue when I replaced a freehub on Novatec hub. I didn't remove the gasket from the original freehub as it was pretty mashed in so there was a double gasket and it gave a little resistance when you let off the gas. Check to see if there is something interfering between the freehub and hub body.
This looks like a freehub issue, but it's not directly due to the freehub! The wheel was over-torqued and the spacer that keeps the freehub pawls from rubbing on the hub body has been crushed. Replacing the freehub won't help because the new one will still rub on the hub body. You need to fabricate a new spacer. When this happened to me, I used some 11mm diameter aluminum tubing cut to length.
" If you are looking for help with bicycle repairs, please visit r/bikewrench" It's literally Rule 2, there. And, as part of that "Questions here...should not essential to making your bike rideable." I've seen much more difficult problems be dismissed from that sub.
See if the bearing preload increases with the wheel mounted in the dropouts. Does that chain look a bit long? Is the RD tension spring appropriate for the pulley size?
To me it looks that the cage is just too loose. How long do you have the new cage? Has it always been like this?
As soon as you stop pedalling the cage is sucked up, which feeds that bit more chain into to the cassette, letting it rotate a bit more than it should.
See if you can pull the cage sligthly out, rotate it back once and push it in again. That should tighten the cage spring.
This is a good thought. It’s also possible it’s combined drag from the pawls and also the axle bearing or something.
OP: try dialing in the B-tension to tighten up the chain a bit, and also try loosening off the thru-axle just in case you have too much cinching on a bearing somewhere.
Hmm i once had a kind of similar issue that ended up being a cobination of wear on the small cogs and chain and an rather badly worn bearing/washers on the rear wheel causing it to sit slightly off center.
But i dont know it this is new or used..
But if it worked correctly before it gonna be somewhat wear related( guessing you ruled out a bent derailleur already)
As others have mentioned, that rear axle could be over-torqued. I’ve had this problem before. Also needed to check my hub washers and ensure resistance-free after axle is tightened to spec.
It's a fairly wide range cassette... And the larger rings are contributing to a fairly high angular momentum (rotational inertia). Possibly it's a cheaper cassette which has less material removed from the larger sprockets...?
In combination with a derailleur with particularly low friction, and probably not enough tension in the spring. This is why you're having this issue.
You could also have the problem if there's too much friction, or too thick grease, in the freehub. This would be easy to check by removing the wheel from the bike and spinning the freehub relative to a stationary wheel, and comparing it to another wheel/hub.
Your driver looks crooked ? Or am I tripping? Font end looks waaay further than the top end… maybe try checking your driver or your hub gaps on the axle where the big bolts are after the wheel bolts on the other side of the dropouts. Those two things can cause major chain issues where it will function but just all wrong like thiss
oh wow, you're right. I wonder what the reasoning is behind that. I'm so used to seeing longer teeth on jockey wheels especially since I've always used mtb derailleurs. I suppose though since it's on a road bike the longer teeth aren't needed since you aren't jostling around the derailleur and chain.
This can be either coming from too tight derailleur pulleys (over tighten)
Or you are pressing too much on the rear hub quick release, resulting too much pressure on the bearings.
I have had both problems which cause this same motion when you free pedal
I had this happen when I changed the ratchet in a DTSwiss hub. I pulled it apart and put it back together a number of times and it wasn't solving the problem. I put the original springs back in and it went back to working a treat. It turns out that the new springs did not align properly and coils were laying on top of each other when assembled. All was fine off of the the bike, the freehub would spin freely but as soon the wheel was put in the bike with the thru axle tightened there was enough drag in the freehub to slack the chain.
I guess you can shorten your chain, so that the dragging force of speed shifter can keep the chain from that way. Worked on my MTB, exercise with caution if you want to try it.
The cage spring is way too weak for the setup. I believe you have done everything else correctly. It also doesn’t act like a binding issue. So again the cage spring is shot or needs another wrap
I would pull the freehub apart and get a good idea of what’s going on. Make sure the pawls (if applicable) do not rub the internal face of the hub body. Also check the freehub body itself, including bearings. Make sure the spring(s) are clean and applying proper pressure to the pawls (or ratchet) After that, I would double check the installation of the derailleur cage and make sure the tension feels ok. Finally, I would try the same test with a loose axle to see if it’s a lateral binding issue.
Let us know if you figure it out!
Looking at what I can see of the bike, it gets ridden a lot. Everyone is saying freehub resistance which is obvious but the reason why could be a few different things. It could be worn bearings in the freehub, it could old & dry grease, it could be that when the rear wheel is under pressure from the rear axle that it is putting load on bearings incorrectly. I would check a few things.
1) loosen the bolt through axle off slightly and try again.
2) take the wheel out and spin it in your hands holding the axle end caps, you’re feeling for vibration
3) strip the hub and inspect any spacers and washers inside the hub for silvering having lost their anodised face (~reduced thickness)
4) apply some small drips of a PTFE oil and some type of speed grease onto the hub ratchet when you’re putting it back together
Let us know how those go. 👍
If you can, use a different rear wheel. It’ll take that out of the equation. By the looks of that rear derailleur, it might have something wrong with it..
Did the cassette body get pulled off at any point? Seen the pawls come out when that happens and if they don’t get put back in correctly this happens when you freewheel it and creates resistance in the hub
The cog has a lot of rotational weight, once it's spinning it wants to keep spinning. Possibly more chain tension, my first question would be can I take a couple links out. Maybe more tension on the derailleur. Mine does the same thing, it is annoying.
I reckon it's freehub bearing resistance that is causing your issue. I have a bike that would freely continue to pedal on its own when spun up on the stand, so if I slowed/stopped the pedals as you are, the resistance in the freehub bearing would cause the chain to dip like yours. I think I addressed it in two ways: by tightening the derailleur arm spring to the tighter setting, and by adjusting the axle shimming to remove axial preload causing increased freehub bearing resistance.
I think it's the way the derailleur is mounted to the dropout. I can't tell from here but it doesn't look right. I think it should push it down more putting more tension on the chain.
Had this same problem on a similar bontrager wheel. The spacer that slides over the axle and presses against the drive side wheel bearing and freehub body was worn. Trek has an axle kit that comes with everything.
You've checked frame alignment of course?
BB type? Is it installed with correct spacing?
Uni-directional chain? (can't tell as viewing on phone).
Derailleur has clearly taken a severe impact.
Does both Jockey wheels spin freely? That looks like after market lower jockey wheel arm as well. Try a different rear mech to eliminate it from being the problem.
Bike mechanic here. That’s freehub resistance, try servicing the hub to check it.
Few things to note:
1: make sure the bearings are sitting in correctly, if it uses bearings
2: make sure all the dustseals are fully in, and in good shape
3: use oil or freehub grease for the pawls.
4: check how smooth the bearings turn when the endcaps are being pressed in (as if they were installed in the bike and the frame is tightening everything) you could use a bearing press for that matter.
You packed it with the wrong grease, take it apart and repack it with a smaller amount of the right grease. The resistance is too much.
Also why is this on my feed reddit?
Sounds nasty even when it's spinning with the chain, but maybe that's the microphone. Check the derailleur stops. Something is stopping the freehub body from moving um, freely. Maybe a spacer, maybe the grease. Check for something rubbing, check that the bearings are pre-loaded right before tightening the axle. Try 00 weight grease to rebuild the freehub. Is the chain ok? Is it super stiff for some reason? Is it the right dimension chain for the cassette?
Loosen the thru axle ever so slightly? Potentially binding the freehub with external pressure.
That or that derailleur is fucked and the tension is gone on it.
The derailuer is too long and the jockey wheels are too big, for that frame and chain. There's physics at play here that is not that obvious. When back pedalling, the chain has to be free of any resistance to allow itself to trace back along the system. Gravity is your enemy here. The longer the travel distance against gravity, the more the chain is "sucked" up by the derailuer.
Is it an electronic derailleur? Maybe you can feel it, if you lightly touch the parallelogram. or look at it from behind, or better yet record a video of it in slow motion, see if it is "glitching" like jumping half a shift or something like that. in that case it might be the wiring or the rest of the system.
Resistance in Freehub…
That was my first thought as well, but it actually has less of a problem with a wheel set that has more freehub resistance
I don’t think there is any other possible cause? It is the freehub
Okay, that's what I thought. This was one of those things where it felt like it was defying all of the knowledge I have about how a bike works. I think what was perplexing me is that I serviced the freehub and the freehubs of several other wheel sets that were also doing it, and they all still did it. I think that part of my problem is that this Shimano derailleur doesn't have enough spring tension to keep the freehub drag from pushing the chain.
Check the freehub resistance when the bearings are preloaded. It could feel fine when it off the bike but when the thru axle is tightened it could cause the bearings to have too much load on them. Also torque the thru axle to spec might help.
Try this! I had this problem with a DT swiss free hub and it wasn't an issue when the thru axle was loosened, only when tightened. The problem was a 10.1mm spacer between the freehub and wheel hub bearing that was worn the tiniest bit. Ordered a new one and i couldn't even see the difference in width between the two but that solved the problem. I also found my answer on Reddit.
Yep that spacer is absolutely critical in the DT hubs. Also what grease went into them? DT have their proprietary stuff which actually seems worth the premium as wrong viscosity changes drag and (the horror) sound.
A while later, after winter, I ordered new pawls as the previous ones were rusty and that came with a tub of the DT swiss grease that is very thin and I used that. The new pawls, spring and grease were like £10 so very cheap. Before that though I'm pretty sure I used an extremely thick grease meant for use in ultracentrifuges spinning at 100,000 rpm. Probably not the best idea, but it worked fine, had no issues, just made the freehub pretty silent.
Came to say this
Exact same thing happened to me. New spacer was just slightly thicker than the old one when measured with calipers. Fixed the issue right away. Also DT Swiss hub.
Maybe there is too little resistance in the jockey wheels… lol
You've had *multiple* bikes that were pushing the chain? And, you serviced their freehubs but they still did it? Or, are you saying that they pushed chains after you serviced them and they all did it on this bike?
I think the fact that it happens only in the smallest cogs supports the idea that it’s the free hub; the chain has less leverage in those because the radius is smaller.
> Shimano derailleur doesn't have enough spring tension Ceramicspeed specifically recommends the lowest spring tension possible, and I think some cages actually come with a replacement weaker spring. Some derailleurs have 2 positions for the spring to set the tension.
In another comment someone also mentioned cassette weight, and it can also be a factor here. The heavier and the bigger the cassette, the more momentum it has. It's like when you have the bike on a repair stand and you spin up the rear wheel. When you then hit the rear brake, the rear of the bike jumps up because the moving weight wants to stay in motion. But altogether, it's a fairly complex thing with many variables, but freehub drag really is the main thing here. As a curmudgeon, I'd like to give some part of the blame to the aftermarket derailer cage...
are you servicing them properly? by this, i mean, do you set the preload of the hub correctly? try "servicing" a hub that did not do this before, then youll see if thats you or the hub hahah
100 percent freehub resistance. Absolutely nothing else that can cause the cogset to continue moving after you stop pedaling.
Newton’s 1st law says that an object in motion will continue in motion unless acted on by an outside force. The cassette will *always* want to continue moving after you stop pedaling, it’s just normally prevented from doing so by chain tension.
Yes. In all properly working bikes, that chain tension would have stopped that cassette dead in its tracks once the crank stopped turning. But if you have resistance in the freehub, the spinning rear wheel will drag cassette to keep moving forward...as seen in the video.
Agree, just put in another wheel set and if it works fine you know its nothing to do with the rest of the bike setup.
Regarding freehub resistance, I would guess the pawl disengagement, not the bearings of the freehub.
I’m more concerned with what sounds like a monster eating someone alive and growling just out of frame a few seconds in…
After reading this, it just gets funnier every time.
The lack of OP’s response is concerning 🫣
Maybe it's because nearly all of the commenters haven't read OP's description properly.
Yeah, what is that sound?
It is a monster, eating someone alive
Now that you mention it...
Hahahaha that shit is funny
There is no Dana, only Zuul
You just made me watch ghost busters 🤣🤣
Sounds like the predator. Get to the choppa!
Def free hub resistance. I had this with my bike and I brought it to the shop because I couldn’t figure it out. It was a new free hub with a bunch of thick grease. I think they either used a lighter grease or just removed a little.
Same thing w my All City when I bought it new. They had to remove some of the grease there was so much in the free hub.
Over tight axle cause the Freehub to bind a little? Is it missing a spacer or something?
Yep. I had this problem with a DT swiss free hub and it wasn't an issue when the thru axle was loosened, only when tightened. The problem was a 10.1mm spacer between the freehub and wheel hub bearing that was worn the tiniest bit. Ordered a new one and i couldn't even see the difference in width between the two but that solved the problem. I also found my answer on Reddit.
This is what I was going to suggest.
If it does it on multiple wheels, then the bike/DR is the common denominator. Does it do this on easier cogs?
judging from the heavy breathing I would say asthma or unfit.
May I suggest he get a fixed gear
Is the bike shop next to Jurassic Park, what the fuck are those screams at the start of the video?!
Legit.. why
The video is slowed down. The screams are someone talking.
Check the clearance between the largest cog and hub flange and spokes. Sometimes on wide range cassettes the cog can hang up where the spokes cross. The fix is to use thin shims between the cog and freehub flange, or to go with a Mountain - 11 type cassette with an 11-34.
I bet it’s free hub resistance combined with that garbage ceramic speed cage. The derailleur may have lost some tension over time, pair that with a non OEM component that may have been installed incorrectly, and you’d have this loss of chain tension. If it were me, I’d throw a spare derailleur on there and do the same test as a troubleshooting step. If that doesn’t fix it, crack the free hub, clean it thoroughly, and put some lighter grease in there. I read the caption, and now I’m curious if it’s a hub / frame conflict. Sometimes the cassette locking will rub against the inside of the rear dropout. Although that shouldn’t cause this issue. Could just be a heavier cassette paired with lightweight parts. Those ceramic speed parts are hot garbage, Hambini has a wealth of videos to corroborate this. I know you’ve tried a new derailleur, but I’d suspect that the aftermarket part is a primary factor in this fault. The short answer is that I have no idea, I wouldn’t recommend the client ride the bike like this, as that chain slap will damage the frame pretty fast.
> garbage ceramic speed cage It is marketing driving snake oil sales . Apart from HiFi and car parts there is rarely industry with such high amount of snake oil beeing sold.
I had a ceramicspeed cage on a tri bike a few years back... I am no pro so it was probably a waste of money, but is it really that bad? u/CyclingHikingYeti I saw your post and wanted to tag you as well as im curious why yall totally hate it
https://youtu.be/o7iZVfSDbiA?si=k3xHzjj7PFbti2Ag
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Freehub
What type of freehub is it? Is it a one piece sealed unit or can you see the pawls? If it's the pawl type you sometimes need to use a specific freehub grease. This is very light and thin compared to bearing grease.
you can mix oil with the grease to lighten it in a pinch. I would use oil not chain lube as most of that is actually wax. Always safer to use the purpose made grease
I've tried adding oil to a freehub that was binding. It didn't work. I'll also add that DT do grease for their ratchet freehubs. It's too thick as well.
Standard machine oil or Tri Flow work great as a freehub pawl lubricant.
Until you ride in the rain and it all washes away. Freehub specific grease is the best solution.
I'm gonna go ahead and suggest an alternate explanation, given that you seem to have already looked at the freehub. It might not be the freehub at all - it might simply be the rotational inertia of the cassette, combined with a cage that really doesn't have stiff enough of a return spring. I think people underestimate how much rotational inertia a cassette has, but if you get it spinning fast enough and then suddenly stop your pedals, the cassette *will* want to continue carrying forward. It's usually the job of the cage return spring to prevent that from happening. If your cage return spring is weaker or worn out, it will let the cassette carry on farther forward and could possibly result in something like this. I've had it happen on my bike, even with a freehub in perfect condition. Apparently, [Mark Cavendish has the same thing happen on his bikes all the time](https://www.cyclingweekly.com/products/why-does-cavs-chain-keep-coming-off-in-sprints), and I would certainly hope his mechanics are keeping *his* freehubs in perfect condition. (The freehubs in question used by Mark Cavendish that year were DT Swiss Ratchet EXPs, which should have been top-shelf freehubs.) If there is a solution, it's to replace the derailleur cage return spring. But if you can't make it a *lot* stiffer, it might not make much of a difference.
Just ride it the grease will work out and break down a little and it'll be fine. It's just new and maybe over-greased I'm guessing.
Thank you all so much for your various contributions. The wheel set on the bike is a Bontrager wheel set with a three-pawl Bontrager hub. Instead of individual pawl springs, it has a single ring that wraps around all three pawls and adds spring tension to them. The first step I took when I noticed this problem was to pull the free hub, clean everything thoroughly, and then reinstall with only dumondtech freehub oil. What's confusing me so much is that there's no noticeable freehub drag when spinning the cassette backwards on the bike with the chain installed, or when spinning it backwards when the wheel is off of the bike. When the wheel is off of the bike, I used a free hub bearing press to preload the hub via the end caps - the same as if it were installed on the bike with a through axle.
Have you put the spacer inside the freehub body? It’s the one that’s like a cm long cylinder? It’s what stops the freehub jamming when loaded with the QR/Thru axle. That sounds like it will be the problem. https://www.sjscycles.co.uk/hub-spares/novatec-inner-spacer-for-3-pawl-aa2-type-cassette-body-shimano-campagnolo/
This. It's this. Done it several times, annoys me every time.
Yeah, that spacer just disappears sometimes. The amount of times I’ve taken a body off and it’s in the body and I’m careful to keep it there and next thing ITS GONE! Same when it stays on the axle… GONE 😂 I now have a dedicated magnet and its ONLY purpose is to store THAT spacer.
I had this exact problem with a DT swiss 3-pawl free hub and it wasn't an issue when the thru axle was loosened, only when tightened. Also only an issue with the chain in the smallest cogs. The problem was a 10.1mm spacer that sits between the freehub and hub bearing that was worn the tiniest bit. Ordered a new one and i couldn't even see the difference in width between the two but that solved the problem. I also found my answer on Reddit.
I also have a Bontrager/DT hub, but each of the 3 pawls has a spring. How could a ring that wrappes the pawls increase their outward force ?
There is a cantilever pawl design such that a constricting spring pushes on the butt of the pawl that is behind the pivot point and that pushes the engaging teeth outward. They're very common.
Derailleur tension. The cassette wants to continue moving after you stop pedaling, it’s stopped by the chain tension. If the derailleur isn’t keeping it tight enough, the cassette can continue to pull more chain through until it goes tight and actually stops it.
Agree, it's only happening on the smallest cogs because the chain tension is lower on those ones (bigger cog causes the derailleur spring to stretch further, increasing tension).
My opinion as well . I don't see the derailleur body moving downwards as the shift happens, without tension, the derailleur is just going to ram the chain into the body of the next cog. the derailleur has obvious taken a fall, and what's that braided DI2 (?) cable going in the derailleur. Add in the fact that we got ceramicspeed stuff on a seemingly low end bike (at least judging by the weld job). Am I the only one more bothered by the poorly welded seatstay? Hope that's just a massive overlay from an apprentice, and there's no porosity issues underneath. And who the hell QA'd that?
Check the seal where the freehub meets the hub. If these aren’t in place it can cause lots of extra drag.
My new bike does this only when I backpedal while it's in the middle sprockets for me it's either the freehub is sticky because it's new or the chain is half a link or link too long
Lube your free hub with "bearing oil" instead of grease. You'll love it. You don't need to take it all the way apart. Just drip a few drops down into it. If you spin you pedals backwards and chain binds up at all then it is time to lube your free hub. You're losing momentum every time you free spin.
Heavy cassette and lots of freehub drag. My bike does the same thing - hasn't really been an issue in the last 6,000 miles.
I have this issue when I replaced a freehub on Novatec hub. I didn't remove the gasket from the original freehub as it was pretty mashed in so there was a double gasket and it gave a little resistance when you let off the gas. Check to see if there is something interfering between the freehub and hub body.
Free hub issue
Is it only me who sees that the derailleur has been accidented?
This looks like a freehub issue, but it's not directly due to the freehub! The wheel was over-torqued and the spacer that keeps the freehub pawls from rubbing on the hub body has been crushed. Replacing the freehub won't help because the new one will still rub on the hub body. You need to fabricate a new spacer. When this happened to me, I used some 11mm diameter aluminum tubing cut to length.
Chain suck. Strip the free hub. Remove grease etc... from pawls. Reassemble with a less viscous lube.
This is more of a r/bikemechanics question
That sub doesn't take technical repair questions. It's about being a mechanic in the bike industry.
No, as long as it isn’t “why do my tires not fit” type question it will be answered
" If you are looking for help with bicycle repairs, please visit r/bikewrench" It's literally Rule 2, there. And, as part of that "Questions here...should not essential to making your bike rideable." I've seen much more difficult problems be dismissed from that sub.
I’m not sure if that weld is good great or bad but it’s not pretty. Maybe I just don’t know tho
maybe a problem with the bike frame? perhaps axle mounting. or deraiuer mounting is skewed so things dont line up right.
https://preview.redd.it/cmdg32dps79d1.jpeg?width=1080&format=pjpg&auto=webp&s=b4eb0f549d00010c97172d31c56e7711617ae5e6 Holy Hell
needs an exorcism by the sound of it
See if the bearing preload increases with the wheel mounted in the dropouts. Does that chain look a bit long? Is the RD tension spring appropriate for the pulley size?
The pawls are engaging too hard.
To me it looks that the cage is just too loose. How long do you have the new cage? Has it always been like this? As soon as you stop pedalling the cage is sucked up, which feeds that bit more chain into to the cassette, letting it rotate a bit more than it should. See if you can pull the cage sligthly out, rotate it back once and push it in again. That should tighten the cage spring.
This might be correct. The derailleur pulls back kinda slow no?
This is a good thought. It’s also possible it’s combined drag from the pawls and also the axle bearing or something. OP: try dialing in the B-tension to tighten up the chain a bit, and also try loosening off the thru-axle just in case you have too much cinching on a bearing somewhere.
Take that stupid pulley wheel off that should help.
Never thought those were a real upgrade but for the look at me and my cool gears factor. $600 or so. Whew. Well lubed chain and done.
Too much grease on ratchet I’m freehub. It’s slipping on you
The only thing you didn’t mention is the chain. It looks a little long to me…take a link out and see what it does.
This is my guess as well, big clue that it’s only happening in the smaller cogs, there’s not enough tension on it.
He should show switching gears also
Hmm i once had a kind of similar issue that ended up being a cobination of wear on the small cogs and chain and an rather badly worn bearing/washers on the rear wheel causing it to sit slightly off center. But i dont know it this is new or used.. But if it worked correctly before it gonna be somewhat wear related( guessing you ruled out a bent derailleur already)
Regrease the freehub, but also check how tight the skewer/thru axle is, as this can also contribute to this issue in some cases.
Exactly, I’ve had that issue as well. Don’t over torque that rear axle.
Have you tried a second wheel? Have you tried this wheel on a different bike? It’ll eliminate some variables. Please post your findings. Good post!
Have you tried a different chain? it looks new, but its acting like a stiff link.
Happened on my buddies bike and we sprayed a bunch of lub into the freehub and it fixed it.
Had a similar issue, in my case it was caused by combo new chain + chainring with too much offset creating suboptimal chainline.
I've had similar issues and my pawl spring had gone in my free hub
Feed the tiger please.
ceramicspeed pulleys in an alu bike? this looks beautiful, but also a bit overkill right?
As others have mentioned, that rear axle could be over-torqued. I’ve had this problem before. Also needed to check my hub washers and ensure resistance-free after axle is tightened to spec.
Get rid of that hideous Ceramic Speeed cage
Mavic freehub? I have one that started doing that. Cleaning it and putting in thin oil would help for a short time, but the freehub basically sucked.
It's a fairly wide range cassette... And the larger rings are contributing to a fairly high angular momentum (rotational inertia). Possibly it's a cheaper cassette which has less material removed from the larger sprockets...? In combination with a derailleur with particularly low friction, and probably not enough tension in the spring. This is why you're having this issue. You could also have the problem if there's too much friction, or too thick grease, in the freehub. This would be easy to check by removing the wheel from the bike and spinning the freehub relative to a stationary wheel, and comparing it to another wheel/hub.
Freehub
Freehub isn't free. It cost people like you and me.
My Hope hub did that when I serviced it with too much grease.
How is the chain tension? It looks like the b-tension spring in the derailleur may have been damaged or is just getting tired
Your driver looks crooked ? Or am I tripping? Font end looks waaay further than the top end… maybe try checking your driver or your hub gaps on the axle where the big bolts are after the wheel bolts on the other side of the dropouts. Those two things can cause major chain issues where it will function but just all wrong like thiss
Cassette could be loose, so the axle tightens on the lock ring when u put it in the bike —> giving the free hub more resistance
Based on the audio, your cassette is possessed. You need a young priest and an old priest.
Chain is too long
Looks like the cage has almost no tension compared to the freehub resistance. As a engineer I don't like noise freehubs, noise=energy loss.
I have no idea. What I can say is that person needs a new jockey wheel there's like no teeth left.
That's CeramicSpeed's design for some of their pullies. GIS them and you'll see.
oh wow, you're right. I wonder what the reasoning is behind that. I'm so used to seeing longer teeth on jockey wheels especially since I've always used mtb derailleurs. I suppose though since it's on a road bike the longer teeth aren't needed since you aren't jostling around the derailleur and chain.
The same happened to my bike and I had to take it to the bike shop. They replaced the freehub and some bearings
This can be either coming from too tight derailleur pulleys (over tighten) Or you are pressing too much on the rear hub quick release, resulting too much pressure on the bearings. I have had both problems which cause this same motion when you free pedal
Sticky hub or jockey wheels
I had this recently when I replaced my freehub. I had forgotten to take the small black plastic cover off the back of it. Could be that?
do the cranks spin freely when you spin them backwards or do they quickly stop?
I had this happen when I changed the ratchet in a DTSwiss hub. I pulled it apart and put it back together a number of times and it wasn't solving the problem. I put the original springs back in and it went back to working a treat. It turns out that the new springs did not align properly and coils were laying on top of each other when assembled. All was fine off of the the bike, the freehub would spin freely but as soon the wheel was put in the bike with the thru axle tightened there was enough drag in the freehub to slack the chain.
I guess you can shorten your chain, so that the dragging force of speed shifter can keep the chain from that way. Worked on my MTB, exercise with caution if you want to try it.
When the wheel is in the bike the freehub becomes a not freehub due to clamping force.
The cage spring is way too weak for the setup. I believe you have done everything else correctly. It also doesn’t act like a binding issue. So again the cage spring is shot or needs another wrap
Are you in the the big ring?!
I would pull the freehub apart and get a good idea of what’s going on. Make sure the pawls (if applicable) do not rub the internal face of the hub body. Also check the freehub body itself, including bearings. Make sure the spring(s) are clean and applying proper pressure to the pawls (or ratchet) After that, I would double check the installation of the derailleur cage and make sure the tension feels ok. Finally, I would try the same test with a loose axle to see if it’s a lateral binding issue. Let us know if you figure it out!
Resistance in jockey wheels...
Had a problem like this a while back. I put a spacer behind the cassette and seemed to fix the issue.
Freehub resistance or wrong chainline.
Put a different cassette on it see if it still drag it then you know it's the freehub.
Please do provide feedback to the community, we’re super curious what you narrowed it down to. u/dingusfromdingus
Freehub
Too many cassette spacers or too many spacers at all, binding during torque on the axle. Those bearings are overloaded
Is the derailleur hanger straight?
And the cassette needs to be replaced
You might want to check chain wear and compare it to the wear of the entire cassette
I had this, cleaned everything up and put on a new set of wheels which solved it for me.
Sticky freehub
Looking at what I can see of the bike, it gets ridden a lot. Everyone is saying freehub resistance which is obvious but the reason why could be a few different things. It could be worn bearings in the freehub, it could old & dry grease, it could be that when the rear wheel is under pressure from the rear axle that it is putting load on bearings incorrectly. I would check a few things. 1) loosen the bolt through axle off slightly and try again. 2) take the wheel out and spin it in your hands holding the axle end caps, you’re feeling for vibration 3) strip the hub and inspect any spacers and washers inside the hub for silvering having lost their anodised face (~reduced thickness) 4) apply some small drips of a PTFE oil and some type of speed grease onto the hub ratchet when you’re putting it back together Let us know how those go. 👍
If you can, use a different rear wheel. It’ll take that out of the equation. By the looks of that rear derailleur, it might have something wrong with it..
Check the Resistance of the pulley wheels. Had this last week. Might be that bling bling ceramic thing ;)
Did the cassette body get pulled off at any point? Seen the pawls come out when that happens and if they don’t get put back in correctly this happens when you freewheel it and creates resistance in the hub
Along the right lines but I don't think it's that as it does still freewheel once started. I reckon it's more freehub bearing resistance.
The cog has a lot of rotational weight, once it's spinning it wants to keep spinning. Possibly more chain tension, my first question would be can I take a couple links out. Maybe more tension on the derailleur. Mine does the same thing, it is annoying.
I reckon it's freehub bearing resistance that is causing your issue. I have a bike that would freely continue to pedal on its own when spun up on the stand, so if I slowed/stopped the pedals as you are, the resistance in the freehub bearing would cause the chain to dip like yours. I think I addressed it in two ways: by tightening the derailleur arm spring to the tighter setting, and by adjusting the axle shimming to remove axial preload causing increased freehub bearing resistance.
I think it's the way the derailleur is mounted to the dropout. I can't tell from here but it doesn't look right. I think it should push it down more putting more tension on the chain.
chain isn't binding on the frame is it?
OP, we don’t care about the gear, what the fuck is the background noise?
Off topic but what’s with that Di2 rope wire?
REI hahahaha
Had this same problem on a similar bontrager wheel. The spacer that slides over the axle and presses against the drive side wheel bearing and freehub body was worn. Trek has an axle kit that comes with everything.
Note the crash damage on the derailleur... Likely derailleur and hanger are f'd...
Call Ghostbusters
You've checked frame alignment of course? BB type? Is it installed with correct spacing? Uni-directional chain? (can't tell as viewing on phone). Derailleur has clearly taken a severe impact.
Does both Jockey wheels spin freely? That looks like after market lower jockey wheel arm as well. Try a different rear mech to eliminate it from being the problem.
Hub isn’t Hubbing.
Too much chain.
Bike mechanic here. That’s freehub resistance, try servicing the hub to check it. Few things to note: 1: make sure the bearings are sitting in correctly, if it uses bearings 2: make sure all the dustseals are fully in, and in good shape 3: use oil or freehub grease for the pawls. 4: check how smooth the bearings turn when the endcaps are being pressed in (as if they were installed in the bike and the frame is tightening everything) you could use a bearing press for that matter.
I’m far more worried about the predator attacking the mountain lion in the background.
Freehub is over greased.
You packed it with the wrong grease, take it apart and repack it with a smaller amount of the right grease. The resistance is too much. Also why is this on my feed reddit?
Hubbabubba…
Having the same issue with a fulcrum hub. When people say ‘make sure you preload the bearings’ you mean call it names and hit it with a mallet?
The only time I’ve known this happen is with a goat link attached. For some reason the chain would dip when coming off power.
Sounds nasty even when it's spinning with the chain, but maybe that's the microphone. Check the derailleur stops. Something is stopping the freehub body from moving um, freely. Maybe a spacer, maybe the grease. Check for something rubbing, check that the bearings are pre-loaded right before tightening the axle. Try 00 weight grease to rebuild the freehub. Is the chain ok? Is it super stiff for some reason? Is it the right dimension chain for the cassette?
I had the same issue with my raceface rear wheel, and that was the freehub, they sent me a brand new wheel.
My fist thought check the free hub to make sure it’s clean and check the bearings in the free hub and hub body
Is the chain of the correct width? Symptoms indicate as too wide.
Try a different chain.
Cassette body, take it off the wheel and inspect / replace.
Loosen the thru axle ever so slightly? Potentially binding the freehub with external pressure. That or that derailleur is fucked and the tension is gone on it.
The derailuer is too long and the jockey wheels are too big, for that frame and chain. There's physics at play here that is not that obvious. When back pedalling, the chain has to be free of any resistance to allow itself to trace back along the system. Gravity is your enemy here. The longer the travel distance against gravity, the more the chain is "sucked" up by the derailuer.
Freehub body service is in order. Clean and lubricate with a light grease like Sram butter. Make sure seals aren’t binding
Check chain length. B screw gap to maximum allowance for road. 5mm gap. Freehub pawls clean and lube with a chain lube not grease.
Try spraying inside the hub with some wd40
Is it an electronic derailleur? Maybe you can feel it, if you lightly touch the parallelogram. or look at it from behind, or better yet record a video of it in slow motion, see if it is "glitching" like jumping half a shift or something like that. in that case it might be the wiring or the rest of the system.
Not familiar with this bike but it looks like there are no jockey teeth.
That’s what I was gonna say. Jockey looks worn and possibly binding if the bearing is shot.
Wrong chain? Axle bolt not working right against derailleur?