I have an Ultegra 6700 (?) group on my time. It came with the standard Crank. I probably need a compact on this thing. Though I've been climbing everything with the 39/25 it would be nice to have a better gear on the hard stuff. I always keep a spare gear or two so most of the hard climbs are being done in a 39/21 and that slows me to a bare crawl.

Will an FSA with a MegaEvo crank fit in the BB that I have or do I have to buy FSA specific?