The chain is throwing in any of the lowest five cogs. I've tried everything I can think of. Different derailleur cage, different derailleur, different wheels. None of it is working. It just keeps doing this. My first thought was chain push, but it is much better on a wheel that has much more freehub drag. I've also tried these wheels in different bikes and they don't seem to do it. It's like there's something about this exact combo that's causing the issue.
Neither I nor any of my coworkers can figure out how to fix this problem
byu/dingusfromdingus inbikewrench
by dingusfromdingus
29 Comments
Resistance in Freehub…
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.
I’m more concerned with what sounds like a monster eating someone alive and growling just out of frame a few seconds in…
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.
Not familiar with this bike but it looks like there are no jockey teeth.
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.
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)
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.
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.
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.
Freehub
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.
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.
Regrease the freehub, but also check how tight the skewer/thru axle is, as this can also contribute to this issue in some cases.
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.
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!
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.
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
Is the bike shop next to Jurassic Park, what the fuck are those screams at the start of the video?!
Why are those fancy rollers 300-2000 dollars?
Have you tried a different chain? it looks new, but its acting like a stiff link.
Take that stupid pulley wheel off that should help.
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.
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.
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.
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.
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.
Check chain length. B screw gap to maximum allowance for road. 5mm gap. Freehub pawls clean and lube with a chain lube not grease.