Ok, I just got a 2006 Giant TCR C2 frame/fork, I've got the bike 80% built, but I ran into a big problem.. The front derailleur clamp is too small for the seat tube. What do I do? It's a new 105 derailleur. Do I have to get a different derailleur or what? I've never ran into this problem before. Pic's tomorrow. Thanks in advance.