I am building up a 2006 Giant XTC composite and need a new headset (1 1/8″), the integrated style bearings that came out say 36°x45°. Am I right in thinking a headset using 45°x45° bearings will fit ok, as it is only the 2nd number that relates to the frame chamfer angle?

http://www.chainreactioncycles.com/fsa-orbit-cf-headset/rp-prod12760
This is the one I’m planning to get if that is any help (looks like a pretty good deal to me?)

Cheers.

The 2nd number ’45’ relates to the angle of the contact of the bearing with the frame. The first number ’36’ is the inside bearing contact angle with the race (lower) or centering cone (upper). So in theory yes — but I’m sure I remember 36×45 had an OD of 41mm and the 45×45 is 41.8mm. You’ll need to check this, prob best to measure the inside of your headtube accuratley before you order 🙂