BB question
 

Ok I posted about this on the rodie page but seeing as the mechanics lurk around here....
I am getting ready to upgrade my frame from my 2009 Trek 2.3 to a 2007 Felt F1 i know ill need to upgrade my front der to a braze on but i just wanna make sure the rest of my drivetrain will swap out ok....
All i have been able to find is that the BB on the F1 is 70mm and i cant figure out the 2.3's BB size.
Also if the BB doesnt fit can can i swap it out and get one that does without changing my crank?
Any help would be greatly appreciated... thanks

The factors which determine BB interchange for frames are shell width and thread, and for the newer designs shell diameter. Spindle length, and/or spacers on some BB's determine chainline.

If this BB is not compatible with the new frame, you shouldn't have any problem getting an appropriate BB compatible with your crankset.

I highly doubt your Felt F1 is 70mm bb. If you measure them both very carefully and they are the same number, that BB + Crankset is transferable between those bikes - in your specific case. They are most likely both 68mm/english threaded.