Rear Mech Not Shifting

verloren

I was having adjustment issues with my rear mech last week, which went away after a little tweaking and cleaning of cables. Unfortunately on my last ride I lost the use of all but the largest 3 or 4 cogs on the back, and having just had a little play I've managed to 'simplify' it down so that only the 2 largest work. My shifter clicks through the other positions fine, but the derailler doesn't move (so the cable just goes slack). I'm about to do a more thorough cleaning, but does anyone have any other suggestions?

Spec: Ultegra 9sp cassette and derailler, Tiagra STI shifters.

bill57

I had exactly the same problem a few years back. Turned out to be the bit of cable outer between the mech and the chainstay stop, just full off crud and corrosion. Because of it's location down low it takes a particularly bad hit. Replace it, and fit a new inner, and you should be fine.

verloren

Turns out there was a simple explanation - the shifter end of the cable was down to a couple of strands, and surprisingly that doesn't work so well