You should be okay but the CAAD uses a pressfit BB and the crankset on the 7800 is Hollowtech threaded, so would not be compatible. Don’t know if you could find a pressfit BB that could utilise the Hollowtech’s 24mm diameter spindle, maybe someone else might know. The bearings on a pressfit are internal and those on a Hollowtech are external so might not be possible so you’ll need a compatible crankset.