RD shifting problem

[gongmech]

i Have 2 friends whose XT RDs wont shift smoothly till the smallest cogs on the cassette.....Rear derailleur spring problem?? or cassette and chain problem? I tighten up or loosen the cable, it works for a while, but then goes out again when i test the bike. HELP!!!

[gongmech]

oh, also there is a little screw on the back of the RD which presses onto the frame. How much should i scrwew this in?

[Genesis]

Have you checked the hangers?

 

Are you sure they not slightly bent?

 

Just a thought?

[gongmech]

hmmm good one. will check tommorrow.

[kosmonooit]

oh, also there is a little screw on the back of the RD which presses onto the frame. How much should i scrwew this in?

 

That's the "B" screw, you adjust it so that the RD that its touching the chain against the sprocket on the cassette then back it off a few mm, normally done when the chain is on the largest ring on the back. It's an important adjustment: check the instructions and procedure for that product. If its not right, it wont guide / hold the chain properly on the cogs and can keep jumping gears and we all know how irritating that is.

 

Otherwise siff cables can mean sticky gears, or the mechanism if the quad on the RD is bunged up, take it off and check how easy it moves, use penetrating oil if need be.

 

Hope that helps: Persist!

Edited December 7, 2010 by kosmonooit

[gongmech]

Thanx guys. will let u know how it goes..So much info into the small brain.