Chain skipping
Discussion
After some suggestions as to what may be causing my chain to skip as its driving me nuts!
The chain seems to skip only when under load and only when in 1st or 8th gear. It doesn't look like it's trying to move up or down the cassette when it's doing it but I cant be 100% sure
It's a brand new 10 speed, 11-46 cassette, brand new chain, brand new shifter with a new cable.
I've tried adjusting both limit screws and the b tension screw. I've also removed the drive side BB spacer in case it's the chain line. I've checked for bent links in the chain, can't see any damage on the derailleur or jockey wheels and also made sure the cassette is torqued properly and the rear axle is tight
I've now run out of things I can try, Google searches tell me the cassette or chain are worn but they're both new so I'm ruling that out.
Help!
The chain seems to skip only when under load and only when in 1st or 8th gear. It doesn't look like it's trying to move up or down the cassette when it's doing it but I cant be 100% sure
It's a brand new 10 speed, 11-46 cassette, brand new chain, brand new shifter with a new cable.
I've tried adjusting both limit screws and the b tension screw. I've also removed the drive side BB spacer in case it's the chain line. I've checked for bent links in the chain, can't see any damage on the derailleur or jockey wheels and also made sure the cassette is torqued properly and the rear axle is tight
I've now run out of things I can try, Google searches tell me the cassette or chain are worn but they're both new so I'm ruling that out.
Help!
Ruling out wear. check the derailleur is mounted correctly & isn't bent. Also that the chain is mounted the right way round. Shimano chains are directional & after that. check it's the right chain for the cassette. Chains are built to different widths depending on the cassette eg.a 12 speed chain is narrower than a 10 speed as the cassette has more sprockets & therefore less space. Unlikely but not impossible the factory has fitted incompatible parts.
Otherwise skipping in top or bottom gears is almost always limit screws.
Otherwise skipping in top or bottom gears is almost always limit screws.
bobbo89 said:
I've always found with drivetrains that when setting them up in the garage things appear to work fine but then not so when actually riding it. Works fine going through the gears in the stand but introducing load will find those slight mis-alignments.
This drives me mad. My middle three gears are popping out under load at the moment and it's like stalling at traffic lights, the looks as the crunch reverberates!
Check for a tight link in the chain - especially if it’s been joined with a rivet rather than a quick. A tight link can take a ‘set’ as it goes round the pulleys and fail to mesh correctly with the sprocket on the unloaded side and then come off the loaded side with a bit of a thump.
There are a few things which can affect chain skipping.
If you've ruled out the obvious worn chain and sprocket, it points towards indexing, alignment, flex under load, slack and movement in components...
Something is causing the chain to want to move off the sprocket.
That can be anything that allows the sprocket to move out of line.
Wheel bearings
Frame flex
Freehub bearings
Or anything that allows the chain to change its line
Worn derailleur (pivots in the parallelogram bit, the main pivot on the hanger...)
Worn lay-on pulley bearing, or the pulley cog itself
Chain line just plain wrong?
Hanger bent?
Too many/few links in the chain, so too few links engaged on the rear sprocket?
Shifter not actually pulling the right amount of cable to move the mech to the right place?
components just shyte by design, not up for actual adults standing on the pedals?
I found it enlightening to put the bike on a turbo trainer and get a mate to pedal and brake while I watched and looked for things getting out of place.
You realise that frames bend and nothing is exactly over built.
The movement adds up.
Even with 8 speed, the slack and flex and wobble adds up when you're fettling a vintage bike for the woods.
In my case, a new rear mech and freehub took out a lot of movement. Job done, it's now good enough to call it sorted.
But I realised that people buy new bikes so that every thing is as good as it can be.
And/or more expensive flavours of component, look at a Dura Ace rear mech against a cheap one made of thin bent metal....
If you've ruled out the obvious worn chain and sprocket, it points towards indexing, alignment, flex under load, slack and movement in components...
Something is causing the chain to want to move off the sprocket.
That can be anything that allows the sprocket to move out of line.
Wheel bearings
Frame flex
Freehub bearings
Or anything that allows the chain to change its line
Worn derailleur (pivots in the parallelogram bit, the main pivot on the hanger...)
Worn lay-on pulley bearing, or the pulley cog itself
Chain line just plain wrong?
Hanger bent?
Too many/few links in the chain, so too few links engaged on the rear sprocket?
Shifter not actually pulling the right amount of cable to move the mech to the right place?
components just shyte by design, not up for actual adults standing on the pedals?
I found it enlightening to put the bike on a turbo trainer and get a mate to pedal and brake while I watched and looked for things getting out of place.
You realise that frames bend and nothing is exactly over built.
The movement adds up.
Even with 8 speed, the slack and flex and wobble adds up when you're fettling a vintage bike for the woods.
In my case, a new rear mech and freehub took out a lot of movement. Job done, it's now good enough to call it sorted.
But I realised that people buy new bikes so that every thing is as good as it can be.
And/or more expensive flavours of component, look at a Dura Ace rear mech against a cheap one made of thin bent metal....
I think the others have covered all the possibilities but if you don't have one, get a work stand. I faffed like an idiot for 30 years and getting the bike properly supported; free to spin cranks and wheels and close to eye level makes derailleur adjstment much more easy and pleasant than grovelling around on your knees one hand holding the back wheel up, the other turning the crank and wishing you had a third hand to actually use the tools required for the job.
daihard said:
I'll check the chainring too, not actually sure how to check it's worn tho other than if it's really obvious?
Will check the derailleur bolt too, I'm sure I checked it when I went through the bike to check everything but won't hurt to check again
Cheers
Well assuming you’ve two, does it slip in both?Will check the derailleur bolt too, I'm sure I checked it when I went through the bike to check everything but won't hurt to check again
Cheers
Usually one is a lot more worn than the other. They get sharper and more pointy with wear and often ‘reject’ a new chain.
Chainrings have to be badly worn for skipping at the front end. You'll aways see it best as the chain links move from the guide pulley to the cassette & the best way for that is to put it in a stand & crank it slowly until it skips & the problem becomes visibly apparent. Nine times out of ten, the chain plates will land square on the sprocket edges before dropping into place & that's experienced by the rider as a skip.
Also agree with Bobbo that you can dial in a drivetrain in a stand & it can go out of sync once it's on the ground with load going through the transmission but you should be able to get it at least in the neighbourhood of sorted & leave yourself with minor adjustments. The barrel adjuster is your friend.
Also agree with Bobbo that you can dial in a drivetrain in a stand & it can go out of sync once it's on the ground with load going through the transmission but you should be able to get it at least in the neighbourhood of sorted & leave yourself with minor adjustments. The barrel adjuster is your friend.
Cheers for the suggestions so far all, still feeling rough as hell so not made it into the garage to try any of the suggestions so far. At least it's starting raining now so not feeling as guilty about not riding!
Yes, I have a bike stand, like you say it's essential!
It's a full suspension mountain bike with one chainring at the front. It's not sharper or pointier than the chainring on any of my other bikes which change gear fine so I'm going to rule that out.
It's weird how it's the 1st and 8th sprockets too, the biggest and smallest sprocket on the main bit of the cassette, the 9th and 10th sprockets are separate. Makes me think that's got something to do with that maybe?
Yes, I have a bike stand, like you say it's essential!
It's a full suspension mountain bike with one chainring at the front. It's not sharper or pointier than the chainring on any of my other bikes which change gear fine so I'm going to rule that out.
It's weird how it's the 1st and 8th sprockets too, the biggest and smallest sprocket on the main bit of the cassette, the 9th and 10th sprockets are separate. Makes me think that's got something to do with that maybe?
daihard said:
Cheers for the suggestions so far all, still feeling rough as hell so not made it into the garage to try any of the suggestions so far. At least it's starting raining now so not feeling as guilty about not riding!
Yes, I have a bike stand, like you say it's essential!
It's a full suspension mountain bike with one chainring at the front. It's not sharper or pointier than the chainring on any of my other bikes which change gear fine so I'm going to rule that out.
It's weird how it's the 1st and 8th sprockets too, the biggest and smallest sprocket on the main bit of the cassette, the 9th and 10th sprockets are separate. Makes me think that's got something to do with that maybe?
There’s a good GMBN video on YouTube of Doddy showing gear set up from scratch. This is the vid I always use as I forget the screws every time Yes, I have a bike stand, like you say it's essential!
It's a full suspension mountain bike with one chainring at the front. It's not sharper or pointier than the chainring on any of my other bikes which change gear fine so I'm going to rule that out.
It's weird how it's the 1st and 8th sprockets too, the biggest and smallest sprocket on the main bit of the cassette, the 9th and 10th sprockets are separate. Makes me think that's got something to do with that maybe?
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