nesdog

I've got a Giant OCR2 with a Tomson Elite post. I noticed the post slipping the other day and went to adjust. When I pulled up on the post, a shim came up with it.

Giant specs the post as 27.2 and that is apparently what the post is. Now I'm wondering if the LBS put the wrong post in years ago and simply used a shim to make up the difference.

First, is using a shim common with seat posts? Second, should the shim make any difference when it comes to properly tightening the post...it seems like I'm not able to hand tighten the bolt quite as much as a year or so ago. (maybe that is just the bolt but want to rule out the shim as any reason for anything). Third, shouldn't the shim stay in the tube rather than coming up with the post?

The LBS suggests getting another Elite in the correct size and doing away with the shim but that then becomes a $100 day. Is it necessary?

Thanks..

FBinNY 

Shims are very common with carbon frames, though in most cases I wouldn't call it a shim but a liner.

It isn't rare for aluminum seat posts to seize in carbon frames. Fitting an aluminum liner protects the seatpost from the carbon, and many manufacturers do so, usually bonding them in permanently.

In your case, Giant specs the same post you have, so it's a safe bet that the liner was original to the frame. Push it back in, then adjust and tighten the seatpost and you're good to go.