Front der shifter cables and carbon frames

I have noticed that many carbon frames have a pass-through in the bb
lug for the shifter cable and some come with a teflon (?) tube to
prevent wear on the frame by the shift cable.

It has been suggested that this tube is unnecessary and may even cause
shifting problems. Additionally, the shifting will be fine without it
and the groove that would be worn by the cable would never affect the
integrity of the frame (which I can believe).

Anyone with practical experience one way or the other?

TIA

D'ohBoy

On 27 Feb 2006 05:57:17 -0800, "D'ohBoy" wrote:

It has been suggested that this tube is unnecessary and may even cause
shifting problems. Additionally, the shifting will be fine without it
and the groove that would be worn by the cable would never affect the
integrity of the frame (which I can believe).

Anyone with practical experience one way or the other?

I've gotten smoother shifting using a plastic tube. I don't even
think that they are PTFE. Keeping the pass through clean, whichever
method you choose, is requisite.

I have also used a piece of plastic tubing in plastic cable guides.
The guides, particularly on wide downtube frames, get slots cut into
them with time.