Originally Posted by
Scrodzilla
For most bikes with a 27.2 seatpost, the correct seatpost collar/front derailleur size is typically 31.8mm.
Your lbs should have a bunch of shims on hand.
Ah, I get it. I measured my old frame and new one, with a 31.6 seatpost, it looks like my old one had a 35mm FD clamp, and the new frame looks like it needs (like you said) a 31.8mm clamp.