Internal cable issue

[okcmaestro]

[attachment=4841]I have a non-branded carbon fiber TT bike (Cervelo P3) purchased on the internet. It looks very similar to the picture posted. The problem is once the shift cables are installed and adjusted the shifting only works a couple of times or less and then hangs up and the cable binds up somehow and the bike will not change gears. When you take the tension off, the cable will slide back and forth thru the housing without hanging up. Has anyone experienced this before? Is there a way to replace the internal housing? I think the frame is not hollow and has plates that the housing must travel through to get from one end to the other. Any thoughts will be greatly appreciated.

OKC

[DaveM]

No idea on the frame. But if the cable slides smooth when you move it by hand, my guess would be that the shifter is binding, not the cable. YMMV

[cny-man]

In which direction does it bind, or is it in both? Is it both cables, or just one? As for replacement, although most are similar there is not a standardized way internal routing is handled.

Your problem may need an in-person evaluation/assist.

[okcmaestro]

Bike shop removed shifter and just pulled on the cable by hand and it bound up. It binds when pulled in either direction. The external housing was replaced. The top piece and original cable had rust on them. The problem was initially on the front chain shifting but now is on both, it is almost like there is something loose inside the housing that gets caught when under pressure. Thanks for input.

OKC

[Drekkly]

(01-25-2014, 07:32 PM)okcmaestro Wrote:  Bike shop removed shifter and just pulled on the cable by hand and it bound up. It binds when pulled in either direction. The external housing was replaced. The top piece and original cable had rust on them. The problem was initially on the front chain shifting but now is on both, it is almost like there is something loose inside the housing that gets caught when under pressure. Thanks for input.

OKC

OKC - got exactly the same frame (Chinese import) and have just had the exact same problem - from mech lost all tension on the first ride out and now I can't get the shifter onto the big ring. Took it to the lbs and they said the internal routing was causing it to bind up somwhere when trying to increase tension. I really don't understand how - have you had any luck getting to the bottom of it? It's only the front mech at the moment but am worried as you say yours is now front and back.??

[okcmaestro]

No one here has an idea other than a carbon fiber repair guy that would cut the bike open and then patch it up. That would cost about what i could get a new frame for , so that is out. Once the front went, I put a couple of hundred miles on it then the back went out.

[nfmisso]

if you have a dentist or doctor friend or lab friend with an x-ray machine.........

[Drekkly]

Is there no way you can run an outer the whole way through for the rear mech?

[nfmisso]

And an off the wall suggestion - convert it to a SS or fixie; or sell the frame to someone who does want to make a SS or fixie, and get yourself a different frame.