Thanks for the response, I'm going with the Dura Ace BB now and will upgrade the crankset later. Reason for the combination now is that is how Felt set up the 2009 B2. Their next bike up is the B2 TT/TTR and has all SRAM Red, then the B2 Pro has all Dura Ace. The standard B2 ($3800) was already more than I could afford at the time so I'm slowly upgrading a few parts. This is really the only area where I scratched my head on the setup, the rest is very good and the bike rides/handles like a dream. Thanks again, I can now purchase with confidence it will work, much appreciated.