Originally Posted by
Cratecruncher
I recently refurbished a bike set up with Campy nuovo record shifters on the downtube. It included removing and polishing the shifter bracket and paint underneath. After a couple of rides I find the shifters are going out of adjustment and the cables are going slack from the bracket slipping down the tube. I can even see an outline of the bracket in the paint that is slightly less sun faded telling me the bracket has slipped yet again! I tried the obvious: tightening the bolt and nut VERY TIGHT but still having the problem. I don't want to shear the bolt off. Anybody got a solution without drilling holes in the down tube?
I have come to believe that removing the clamp to clean polish, etc.causes it to become slightly misshapen and fatigued so it does not "bite" as it did before.
I also believe you need to remove it without spreading it any more than absolutely necessary to retain its original shape as much as possible. I always remove the clamp bolt completely so it doesn't scratch or hamper the process causing you to spread it more to get it off.
Early on I broke a Suntour clamp thinking it was far more robust than it was, I have proceeded with extreme caution ever since and not had one break or slip ever since.
It can also help if the clamp ears are angled so that the band parts contact the tube first, then the ears apply force to the band instead of touching each other before the band at the tube is tight.
One of the many wonderful PITA little niggles that screws up paint and keeps us up at night.
