. Splined bottom bracket for use with Shimano Octalink chain sets. Oversize BB spindle – large 22 mm diameter hollow cold forged chrome-moly pipe billet spindle reduces weight, increases strength and rigidity. Octalink splined axle/crank arm interface – results in more rigid crank assembly compared to square tapered spindle. Sealed cartridge assembly with oversize ball bearings – maintenance-free high efficiency rubber seals keep out dirt, mud and water. Cartridge design allows easy installation without adjustment.