Shimano Road Press Fit Bottom Bracket 41mm Diameter with Inner Cover for 86.5mm -

About the Shimano Road Press Fit Bottom BracketThe Shimano Ultegra level Bottom Bracket English Thread Cups use Shimano HollowTech II technology which uses a wider outer bearing placement and larger axle diameter for increased stiffness and efficiency. While it's sealed design has a minimal bearing interface ensuring smooth rolling and increased durability. The latest version of HollowTech II used here is lighter and has 50% lower rotational friction than previous version.