UKH

Need to replace front derailleur inner as it's stuck to the PTFE liner tube that runs inside the downtube and round the BB and up out to the front mech.

Guy in the shop I was just talking to on the phone doesn't ever replace the liners as they just end up collecting water, he uses stainless cables.

I think I'd be happier putting even a short length of liner round the BB guide as I think running the cable direct on the plastic isn't a great idea.

Comments and advice welcomed. 

Cheers 

Mark

How can it be stuck to the PTFE?

It just is stuck internally. Had the cable detached from mech and removed from the frame and the original liner and inner cable are stuck together so inner won't slide and operate the mech.

There is discolouration and damage of the liner tube so I suspect water/debris ingress over time.

Regards 

Mark

Hi Mark, do you mean one of these?

https://images.app.goo.gl/HNrT57RkcXyBrMNp7

No, though the plastic inside the frame under the BB is shaped like that.

The ptfe line went right from the frame entry point round the BB and poked out up to the front mech, it's similar to this 

https://www.amazon.co.uk/JAGWIRE-SLICK-LINER-ELITE-SHIFT/dp/B00UCMLVY0/ref=...

It's got one end like a trumpet bell that is at the entry point on the downtube.

Having sorted it now, the original inner cable must have had a ptfe or similar coating on, this had degraded and was separating from the cable and bunching up which then clumped up and wedged the inner inside the ptfe liner.  There was also water inside the liner tube.

Cheers

Mark

Glad you got it sorted