Need help with seat part.

[Frinton]

I have a Giant OCR2 (MY2005). I need a new seat-post clamp and cannot figure the size. I called 10 different Giant dealers and got 7 different answers. The seat post is 27.2 millimeters and there is a metal shim in the seat tube. Does anyone have an OCR model that knows the answer to my problem?

 

[gclark8]

Do you not have a vernier caliper to measue with?
It should be the same diameter as the front derailleur clamp, 28.6mm or 31.8mm, probably the latter if it uses a shim. (some Giant MTBs are 34.9)

 

[Frinton]

Do you not have a vernier caliper to measue with?
It should be the same diameter as the front derailleur clamp, 28.6mm or 31.8mm, probably the latter if it uses a shim. (some Giant MTBs are 34.9)

For anyone that wants to know, it is a 34.9.

 

[gclark8]

Thanks for the reminder, I picked one up from my LBS on the way home today!! Yes, 34.9, allen key type.