MTB Chain Issues- Advice Please
Discussion
Total noob to biking so you'll have to bear with me. Bought a well battered 2009 Charge Duster on the cheap, had it serviced this week at a local bike shop- a new bottom bracket, chain and rear gear cassette later and I was told it was 'tip top'. Just been out for a ride though and the chain keeps slipping (not just after a gear change but when peddling along in-gear), getting tangled on the frame, and came off altogether a few times. Is this normal or should I be taking it back to the shop again?
Yep take it back but sounds like it could be a frozen link. When the new chain is put on the pin tool pinches the sides of the link causing two segments to be locked together or tight. At low chain speed it isn't noticeable as the link still gives but as chain speed goes up it causes the chain to miss the teeth on the rear cassette or chain wheel or both.
You can check each link in the chain - they should all move freely.
You can check each link in the chain - they should all move freely.
caiss4 said:
Yep take it back but sounds like it could be a frozen link. When the new chain is put on the pin tool pinches the sides of the link causing two segments to be locked together or tight. At low chain speed it isn't noticeable as the link still gives but as chain speed goes up it causes the chain to miss the teeth on the rear cassette or chain wheel or both.
You can check each link in the chain - they should all move freely.
Is that fixable? Or does it require a new chain?You can check each link in the chain - they should all move freely.
I'll tell you exactly what this is - because I've just had the same!
I decided to replace the chain and rear mech on my well-used '99 Rockhopper. But like you, I left the crankset as it was.
Riding it, the chain kept being pulled round and up the back of the crankwheel, jamming into the frame.
What happens is that the old chain obviously wears and gets worn / slack inside the links.
Then, if you look at the crankwheels - especially the lowest (smallest) gear, the load-bearing faces of each tooth (i.e the front of each tooth that carries the drive pressure from the chain rollers) get worn so that the metal 'splays' outwards from each tooth - and there's a lip of metal that appears on the sides of each tooth, on the front edges.
This is fine with the old chain as it wears inside to accommodate the lips. However, a new chain will pick up on those lips and hence be carried round the wheel instead of pulling away along it's normal run along to the rear mech.
Two solutions: Either replace the front crankwheel(s), or remove them and carefully file the lips away from each side.
On mine it was only the small wheel that had this bad - so I replaced it with a new one (£15).
It's all now fine
I decided to replace the chain and rear mech on my well-used '99 Rockhopper. But like you, I left the crankset as it was.
Riding it, the chain kept being pulled round and up the back of the crankwheel, jamming into the frame.
What happens is that the old chain obviously wears and gets worn / slack inside the links.
Then, if you look at the crankwheels - especially the lowest (smallest) gear, the load-bearing faces of each tooth (i.e the front of each tooth that carries the drive pressure from the chain rollers) get worn so that the metal 'splays' outwards from each tooth - and there's a lip of metal that appears on the sides of each tooth, on the front edges.
This is fine with the old chain as it wears inside to accommodate the lips. However, a new chain will pick up on those lips and hence be carried round the wheel instead of pulling away along it's normal run along to the rear mech.
Two solutions: Either replace the front crankwheel(s), or remove them and carefully file the lips away from each side.
On mine it was only the small wheel that had this bad - so I replaced it with a new one (£15).
It's all now fine
What Ray says is true. However, o/p states chain slipping rather than "sucking" and jamming in the chain ring.
It could simply be the indexing on the rear derailleur needs tweaking to avoid intermittent half-changes. This is where the chain climbs/drops as if changing gear but doesn't complete the move and goes back to where it was.
Small adjustments can be made by turning the cable adjuster at the gear lever end to lengthen/shorten the gear cable run.
It could simply be the indexing on the rear derailleur needs tweaking to avoid intermittent half-changes. This is where the chain climbs/drops as if changing gear but doesn't complete the move and goes back to where it was.
Small adjustments can be made by turning the cable adjuster at the gear lever end to lengthen/shorten the gear cable run.
If it's 'slipping' ie feels like it's jumping forward a link when you apply pressure to the pedals, or if it's catching in the rear deraillieur then it's probably the tight/frozen link problem. Find the link and free it with a gentle sideways twist.
If, on the other hand, it's being caught and pulled upwards by the chainwheel instead of running freely towards the back of the bike, then that's 'chain suck' and is a symptom of fitting a new chain to an old, worn chainwheel: there is a mismatch between th epitch of the unworn chain and the pitch of the worn teeth on the chainwheel causing the two to grip one another. New chainwheel(s) needed.
If, on the other hand, it's being caught and pulled upwards by the chainwheel instead of running freely towards the back of the bike, then that's 'chain suck' and is a symptom of fitting a new chain to an old, worn chainwheel: there is a mismatch between th epitch of the unworn chain and the pitch of the worn teeth on the chainwheel causing the two to grip one another. New chainwheel(s) needed.
Looks like Ray was spot on- just taken the bike down the shop and been told it is 'chain suck', and the chain is now damaged as a result, hence the slipping. Yet another new chain and 2 new chain rings at the front required. Shop agreed to stand me the cost of the labour as this should have been picked up when it was serviced, which seems raesonable.
Thanks to all for the advice- sounds like I need to read up on servicing/maintainance next rather than just scouring the OS maps for thing to ride over.
Thanks to all for the advice- sounds like I need to read up on servicing/maintainance next rather than just scouring the OS maps for thing to ride over.
Glad to hear you got it sorted. I've also learnt from this thread as the problem I had was definitely a frozen link but I reckon I could well experience 'chain suck' next time as both my current chain and chain wheels(s) are of a similar age (Read that as my chain should have been changed ages ago!)
spoonoff said:
Looks like Ray was spot on- just taken the bike down the shop and been told it is 'chain suck', and the chain is now damaged as a result, hence the slipping. Yet another new chain and 2 new chain rings at the front required. Shop agreed to stand me the cost of the labour as this should have been picked up when it was serviced, which seems raesonable.
Thanks to all for the advice- sounds like I need to read up on servicing/maintainance next rather than just scouring the OS maps for thing to ride over.
Thanks to all for the advice- sounds like I need to read up on servicing/maintainance next rather than just scouring the OS maps for thing to ride over.
Heh - glad it's sorted now for you though.
Mine also wrecked the new chain like yours - which my Local Bike Shop also swapped free for me, as they had told me the front chainrings would be fine :/
daz3210 said:
Is there an easy way to tell a chain needs changing? I mean is there a look to it or is it more techinical?
It's more technical 
You can buy a chain wear gauge from ebay for a couple of pounds - it measures stretch between the links.
Or pop into your LBS who if they're anything like mine, will measure it for free for you (hoping you'll buy a chain!)
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