Splined bottom bracket designed for use with Shimano road Octalink crankset Oversize BB spindle - large 22 mm diameter chrome-moly hollow pipe billet spindle reduces weight, increases strength and rigidity Octalink splined axle/crank arm interface - results in a more rigid crank assembly compared to square tapered spindle Maintenance-free sealed cartridge design prevents corrosion and is easy to install Aluminium adapter Average weight 250 g