Re: Fine Tuning Shifting

On 7/25/2024 2:58 PM, Tom Kunich wrote:

I have a continuing problem with the shifting goin out of adustment. In one case the right shifter wire partially broke from my over-tightening it but in the other three cases I've had to mark it down to cable stretch which Andrew says doesn't exist. But the wires did not move and the shifting moved towards shifting into a faster gear. I can only assume that wire layup tightened up a little and showing those symptom.
 

Bowden wire bicycle gear wires do not stretch.  Especially modern 'smooth' models which are double-drawn.  Casing seats into ferrules and ferrules into frame stops, but the wires do not change.
Your casing seated into the ferrule(s), the ferrule(s) into frame stop(s), or similar after which the wire will be more slack despite its length being unchanged. Steel wires cannot stretch under any load your hand can generate.
What is a 'wire layup' ?  In any tension-compression control system like a gear wire/casing, the system can loosen but cannot tighten.
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971