My wife started having this problem on her Trek bike. After a couple of
mechanics "re-tightened" it for her I noticed that the clamp was not
totally seated on the tube. It was a very small gap - easy to overlook
- but when I re-positioned it it held fine with the proper tightening.
I'd check that.


--
robbielink
------------------------------------------------------------------------
robbielink's Profile: http://www.trianglecycling.com/member.php?userid=374
View this thread: http://www.trianglecycling.com/showthread.php?t=23675