I'm hoping to replace my ailing 105 BB (-5500) with a DA BB-7700, which is listed as being interchangeable with the 5500 on the Shimano front drive compatibility chart. I've heard from a bike shop that the splines on the DA BB are "a little" different from the 105 and Ultegra BBs, whereas I had thought that they were all Octalink V1. Can anyone give me the real answer?