See video. Chain and pulleys are recently replaced. No matter how I adjust alignment, chain keeps sliding off the rear derailleur pulley. My guess is that the cage is warped, but I can't see how. Maybe I can bend it back, if I can figure out the direction? Thanks in advance for any tips. 🙏
EDIT: Thanks all for the very speedy responses! Chain was definitely too long. I fixed that. Didn't do much to fix the problem by itself, but important. Then I figured out how to bend the cage to resolve the issue. Seems to be working ok? Honestly the bike has enough issues already that I'm not really going for perfect, just rideable. And it seems rideable! So thanks again. (For reference: hanger alignment was checked out not long ago and seems ok. Cabling/shifter prob aren't great.)
Chain keeps slipping out of idler pulley
byu/qualmist inbikewrench
by qualmist
8 Comments
Chain is too long.
Set your chain length correctly and review
that chain sag suggests it’s too long
Are the teeth worn away on the jockey wheels?
Sagging on the chain tells me that’s way too long
Take care if chain length first, then address other possible underlying issues.
— hanger alignment
— cable tension
—cable/housing wear, damage, kinks etc
— pulley cage could also be bent , separate from hanger alignment.
Basically, the rear derailleur has numerous points of adjustment/alignment that need attention. Nothing is independent of the other.
https://www.parktool.com/en-us/blog/repair-help/chain-length-sizing?srsltid=AfmBOop3NTAq3j2UYQIyRCBOfKKyQiT48VpoPusFHouLIDu4ZxNxouBo
These folks wrong, this is caused by bend derailleur cage. Need to straighten that cage or buy a new derailleur. Had the same issue and that’s the only way I could resolve it.