Originally Posted by jklimp

Hello, I just started cycling in September and about 3 weeks ago i finally got a decent bike. It has all 105 components except the shifters are tiagra and sora(both sti shifters). Anyway, a friends gave me a set of dura ace shifters and an ultegra double crankset. The crankset didn't come with a bottom bracket, and my question is, will i need to buy a bottom bracket that is compatible with the ultegra crankset, or is it at all likely that the bottom bracket currently installed in my bike will be compatable with it(The current crankset is a triple 105's). I feel kind of dumb asking about this and I hope i got all the terminology correct, I am doing my best to try and figure out bicycle mechanics.