MegaEXO Omega BB and Hollowtech II crank compatibility? I have a Giant TCX SLR 2 (2014) with a FSA MegaEXO BB and FSA Omega crankset (46/36). 

I just purchased a Ultegra 6750 crankset (50/34), can I run it on my existing BB?

If not, what BB do I need? 

I have read online that it should work as is.
No, the Omega MegaEXO FSA system uses a 19mm spindle diameter and hollowtech II is 24mm. 

FSA BB86 BB (For alloy cranksets) or Shimano BB91 Road Press Fit Bottom Bracket will work.