chain dropping off jockey wheels

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ridesurlys
Posts: 14
Joined: 23 Feb 2014, 4:40pm

chain dropping off jockey wheels

Post by ridesurlys »

Im working on a friends bike and getting a problem i have never had before. In big ring at the front and top three at the rear the chain comes of the jockey wheels and rubs on the cage jamming the drive chain. I know its an extreme gear but normally road bikes can do this. What would be the next thing to check? Have people had this problem
The fat commuter
Posts: 292
Joined: 12 May 2014, 7:54pm
Location: The hilly side of Sheffield

Re: chain dropping off jockey wheels

Post by The fat commuter »

I'm assuming that the chain is clean, well lubricated and not worn.
Brucey
Posts: 44516
Joined: 4 Jan 2012, 6:25pm

Re: chain dropping off jockey wheels

Post by Brucey »

some things that might cause this;

- worn jockey pulleys/chain
- lower jockey pulley fitted the wrong way round ( the teeth are shaped on some mechs)
- fitting the inner cage plate of the rear mech the wrong way round.
- using 8s jockey pulleys on a 10s system

hth

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Mike Sales
Posts: 7882
Joined: 7 Mar 2009, 3:31pm

Re: chain dropping off jockey wheels

Post by Mike Sales »

Are the jockey wheels in the same vertical plane as the cog and chainwheel they are serving?
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
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Tigerbiten
Posts: 2503
Joined: 29 Jun 2009, 6:49am

Re: chain dropping off jockey wheels

Post by Tigerbiten »

I had this year on tour after my mech got bent causing some of the joints worked loose.
This caused it to twist a bit under load.
After that it took a couple of thousand miles for me to wear the teeth of the lower jockey wheel enough for the chain to jump off them.
I solved the problem with a new mech.
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