My Cannondale Synapse is a BB30 (FSA SLK crankset). When I was thinking about swapping my FSA crank to a Shimano crank, I was told that I needed an "adapter" in order to fit the smaller Shimano crank into the BB30 frame. So...if you're building up with Shimano gruppo, that is a consideration. But if you're going with an FSA crank, then it shouldn't be much of an issue since FSA BB30's are readily available.