Internal cable guide gunk

solarflash
solarflash Posts: 102
edited May 2017 in Workshop
The internal cable guide sheath for the rear shift cable is clogged with teflon from previous inners (i think!). I've tried cleaning and flushing with spray degreaser etc which does flush out a fair amount of the black shavings but once cables are reinstalled the shifting is good for a few rides then quickly goes to crap again. Tried replacing the outers and inners a few times so I'm fairly certain it's the internal run of sheathing. Just wondering if anyone has tips for cleaning it completely or if anyone has managed to run a cable liner through the sheath? Any suggestions or tips would be most welcome!

Comments

  • StillGoing
    StillGoing Posts: 5,211
    Replace the sheath? Just run a length over the cable inner and cut to the desired length.
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • sungod
    sungod Posts: 16,523
    if you can't replace the existing guide, you could see if there's enough clearance to run thin wall ptfe tube through it
    my bike - faster than god's and twice as shiny
  • svetty
    svetty Posts: 1,904
    Good excuse for N+1 ;)
    FFS! Harden up and grow a pair :D
  • solarflash
    solarflash Posts: 102
    Yeah I think the guides are taped into the carbon, they don't seem loose so I think removing them might be tricky. Thin wall ptfe sounds good though, I'll see if the jagwire stuff I have from left over will fit through. Svetty, so tempted but trying to hang off till the end of the year start of next!
  • solarflash
    solarflash Posts: 102
    Ok so I managed to get a ptfe liner inside the guide sheaths, the cable now has a clear run and shifting feels very slick. I'm still having some issues though; getting a shift on to the smallest sprocket isn't great, there is a prolonged hesitation but the chain eventually drops down. But at the same time at the lower end of the cassette the shifts start to hesitate as the chain gets further up towards the largest sprocket. I'm using an 11sp hope rs4 hub, 10sp cassette+shifters etc. Limits appear to be set ok. Any ideas?
  • svetty
    svetty Posts: 1,904
    solarFlash wrote:
    Any ideas?
    Try stripping down and servicing the pivots on the rear mech....
    FFS! Harden up and grow a pair :D