Odd shifting problem.

[cyberknight]

Update...
Still getting some odd shifting issues , had a look at the rear mech and the jockey wheel cage is a little loose from the body of the shifter , i can wiggle it a good 1 cm either way by moving the bottom jockey wheel whilst keeping the main body still .
is it toast ?

 

[cyberknight]

Cables, cables.

Well in the end it turned out the rear mech had worn enough to allow the jockey cage to wobble on its mount to the mech body.
After some blagging i mamanged to pick up a replacement cheap and after installation it seems to have sorted it .The old mech i could be there for an hour micro adjusting and i could never get it to shift crisply and consistantly .

 

[accountantpete]

If you are talking about the Jockey Wheel nearest the cassette - that is designed to "float". Ie there should be side to side movement to assist with the shifting.

 

[cyberknight]

If you are talking about the Jockey Wheel nearest the cassette - that is designed to "float". Ie there should be side to side movement to assist with the shifting.

No the whole cage was loose at the point where it joins the main body, enough that the jockey wheels moved to much and the bottom of the cage was moving over an inch .

 

[fossyant]

That's happened to me, I had a Deore LX mech that has worn allowing the cage to flex too much. Replaced with a second hand XT one of the same vintage.

 

[actonblue]

I have just had a similar problem changed all cables inner and outer cleaned the drive train
and it would not shift properly in certain gears. Turns out that the guide pulley was excessively worn and in all probability the excess gunk on the derailleur was masking the effect.

 

[cyberknight]

Finally got round to changing the outer , all sweet again after over a month of living with a 50 /50 chance of the shifter doing anything its nice to know what gear i will be in after i press the shifter .