Evening all, I'm hoping someone can help with my rear gear indexing. I changed the gear cables at the weekend, front worked no problem after some minor adjustment but indexing the rear has opened up a whole world of pain.

It works OK going from the smallest cog to the next smallest then slowly goes out of alignment as the chain moves up the cassette. Fix this but going back down the cassette then doesn't want to play ball. Fix this and it's back to the nightmare going back up. To add to this the triggershifter feels 'mushy' when changing gear, skips gears and I need to press it twice to change between certain gears.

I've checked hanger alignment (good), low and high stop screws (good), chain (new a month ago <0.25 stretch), pulled the cable through finger tight (no good), pulled the cable through very tight (still no good), run through the various methods recommended by Sheldon Brown, Zinn's Art of MTB Fixing and the Park Bumper Blue Book of Fun, sworn at it, been nice to it and tried to catch it unawares – all to no avail.

I'm seriously loathed to go to LBS to fix it as there has to be a knack or various tricks I just don't know about.

Any assistance or tips would be greatfully appreciated or am I just rubbish?

Cheers

bbA

PS It's an SLX derailleur, SLX cassette, SLX trigger shifters and Mudlover cables on a 2008 Rockhopper.

You changed just the inners or the outer cables too? You checked that the end of the outer cable is not split/frayed as that can cause the mushy feeling. Is there a kink in the inner wire, as that can cause excessive friction.

Did you change the outers as well as the cables?

chain on smallest cog.
barrel adjusters central
shifter on '9'
pull cable through hand tight
tighten clamping bolt
shift up to 2 (one click should move one sprocket, or thereabouts)
eye up rear mech, adjust barrel adjusters so top jockey is directly in line with sprocket.
drop down the cassette to 3 (if over or under shifting, fine tune barrel adjuster)

failing that… is your shifter pod rather old?

http://www.youtube.com/watch?v=Z3bVgP_MNwc&feature=related

Do this from the beginning.

barrel adjuster bent or partially stripped cable at mech end terminated wrongly ? had them all had the aghh*/!! was close to selling up and taking up knitting

Worthwile hosing out the cable outers with gt85 (if you didn't already), checking the entrance and exit points of said outers for burrs and starting the indexing adjustments with the chain on the second smallest cog on the cassette.

I've had this… It was the cable routing that caught me out. Things start off fine, but go out of tension rapidly causing no end of teeth gnashing.

Check the cables are in their guides properly, make careful note to follow the routing around the rear stays, bottom bracket and suspension (if the frame is this equipped).

Best of luck!

Everytime I have had this problem, it's been either a kink in the inner or gunked up outer…

Assuming it's none of the above(including too much outer cable around seat tube junction forcing itself into a humped shape), have you clamped the inner cable on the wrong side of the mech bolt, it should be on the outside of the bolt. Getting this wrong causes the sort of havoc with shifting that you're experiencing.(oh, you haven't used brake outer cable either, have you?)

Cheers all for the advice. I'll have another bash this evening otherwise it's knitting for me an a shameful trip to the LBS.

Through bitter experience, I also suggest that you check your mech hanger if you have one. Straight? Fixing bolts secure and not wobbling? cracked and deflecting under load?

Check the cables are in their guides properly, make careful note to follow the routing around the rear stays, bottom bracket and suspension (if the frame is this equipped).

Indeed.
Also check the cable is routed correctly round the MECH as well: You know, the little cams/elbows you sometimes get, and to the correct side of the securing bolt
🙂

if you're using a workstand, be sure the clamp isn't crushing the outer
😳

Mr poddy seconded – have you clamped the cable correctly?

Another one not mentioned I think, and what caused similar problems for me a couple of weeks ago was that I'd replaced the outers too, but the new outer that went from the mech to the frame was too short so there wasn't really very much that came out from the mech parallel to it. Replaced outer with one about an inch longer and all sorted.

…

Check outer cable lengths.

Replace end caps

Replace shifter. The indexing comes from there, rear mech is just a big spring. If it ain't cables then it must be the shifter

Mech hanger bent?

As PMJ and peter proddy said

Has the inner sheath of the Mudlovers been dragged in to the shifter.

Causes all manner of weirdness.

I'll be replacing mine with Flack Jackets or Gore.