For some context. Im very new to cycling and recently one of the jockey wheels on my bike broke so i had to replace both of them. But after i did it for some reason the chain keeps sliping off the upper jockey and the derailer arm doesnt stay down. For some reason the chain seems looser then it is. I checked and the jokey wheels are compatible with the chain and derailer. The chain is compatable with the derailer too. By chance does anyone know how i can fix this issue? (Sorry for the long text)
Derailer arm and jockey issue
byu/Sorry-Violinist-3432 inbikewrench
by Sorry-Violinist-3432
4 Comments
Your hanger looks bent
Is that a new chain? Looks like your chain is too long but also can’t see the whole chain line to determine
I think your derailleur is mounted improperly, there is a limit that should prevent it from going back that far. Take it off and inspect the mounting.
Also like looks like the cage is assembled incorrectly but I’m not entirely sure.
Pretty obvious. Derailleur is not mounted securely to the hanger.
The inner plate of the derailleur arm is bent; you can even see the paint is gone. You’ll definitely make contact with the spokes once it’s in the lowest gear.
And the chain is too long.
First, fix the derailleur.Tighten it properly to the hanger. Then bend it back to shape or get a new one.
Second, get the chain length proper.
You’ll get good quality videos on derailleur mounting, its adjustment and chain sizing from Park Tool on YT.