Originally Posted by
fietsbob
octolink is not backed by more than a few lengths of bb,
square taper you have many options.
7800 is not octalink
Originally Posted by
nwbikeman
The BB I think should but not the components. The 7900 group is not interchangeable with 7800 series as the lever ratios have changed as well as the deraileurs and offset of the crank set, we just built a bike w DI 2 and the 7800 brakes seamed to work fine with the rest of the 7900. Good luck
the op wants a new BB, not a new set of shifters.
Just get any set of shimano road outboard BB cups. Be it tiagra, 105, ultegra or DA, they're all interchangeable between the previous 4500, 5600, 6600, 7800 and current 5700, 6700 and 7900 BB cups.
the best deal, by far is ultegra, but if you want DA BB cups and ceramic bearings, then I won't stop you.