Originally Posted by
BluesDawg
Any bike that the Tiagra crank fits will also take the Ultegra. If the BBs are not the same, get the one that works. It may even come with the crankset anyway.
I wanted to dig into this, from a general knowledge standpoint (as in I have none, and want to learn) So are you saying that (for instance) an ultegra 175 34/50 crankset will fit both in a bike that was designed with bb30, and the same crackset will fit in a bike with an english BB, and all you need to do is change the BB not the crank?