Rotor BB3024 - RD 68mm Steel The Rotor BB3024 - RD 68mm Steel easily accommodates your bike of choice with the press fit, 46mm diameter and 30m axle BB shell. The Rotor PF3024 Steel Bottom Bracket is part of the company's UBB System, which allows far more cranks to work with basically any frame. In this case, the BB3024 allows for the installation of ROTOR 3D24 and Shimano 24mm cranksets. Features Designed to work with BB30 bottom brackets 100% CNC-machined, 7075 aluminum Labyrinth seals prevent bearing contamination Designed to work with ROTOR and Shimano 24mm cranksets | Rotor | Bb3024 - Rd 68Mm Steel 68Mm