fitting new rear mech

hainman

my mates rear mech went t*** up the other day so he bought a new one,went from deore to SLX....

fitted the mech last night,done the H&L screws and the b screw,tightened cable and indexed the gears but they seem to be stuttering a bit,have we missed something??

when it goes up the gears from small to big,it kinda stutters so a wee turn on the barrel adj and it goes ok,get up to big ring on cassette and coming back down it stutters again,wee play on the adj and it goes smooth,basically the middle of the cassette is the problem,it either goes up ok but not down or vice versa....

any help would be greatly appreciated...

thanks
Craig

nicklouse

which SLX mech?

sounds like a mucked up cable if the mech is correct.

Chunkers1980

Or the mech is not screwed on correctly

hainman

9 sp shadow i think,his shifter is a bit sticky,as in when you shift from high to low gears it sometimes doesnt kick back straight away,the mech feels fine on but the new mech hanger he got also seems a mil or 2 thicker than the one that bent,would that be an issue or just done cable???

cooldad

hainman wrote:

or just done cable???

No idea what that means, but if you didn't replace the cable, do so.
The width of the hanger will make no difference if you set the mech up properly.

hainman

yeh sorry meant the cable was done,ie time for the bin,will put new cable on and see how it runs,would that cause the shifter to stick also??

@chunkers1980 isnt it straight forward when screwing in the mech??

Chunkers1980

No, you need the bump in the correct place so the mech sits correctly.

cooldad

hainman wrote:

yeh sorry meant the cable was done,ie time for the bin,will put new cable on and see how it runs,would that cause the shifter to stick also??

@chunkers1980 isnt it straight forward when screwing in the mech??

Yes, I may have mentioned it before, 99.999999999% of shifting problems are due to cables. Sticky shifter may also be worth a bit of a clean or lube.

97th choice

I had exactly the same today when fitting a rear mech. I hadn't routed the cable properly, had it going under the lock nut rather than over it. As soon as I fixed that it indexed perfectly.