I'm looking at ways to make a Claris/Tourney crankset fit a BB30 frame.
I've seen that a "Rotor BB30 to 24mm Steel Road Bottom Bracket" is one of the options to make the two sizes work together.
When you look at the suggested BB for the Claris, for example, it has the octalink axle for the crank arms to attach to. The Rotor product does not. Is it an adapter that the standard BB goes inside, or does it work differently?