Shimano Dura Ace Octalink Bottom Bracket - TrackCompatible with Shimano's Octalink crank arm interface, the Dura Ace track bottom bracket features a hollow spindle to reduce weight with ball and needle bearings supporting it to increase rigidity.Features: 22mm diameter hollow CrMo pipe billet axle reduces weight Splined interface provides a more rigid crank assembly compared to tapered counterparts Compound bearing structure - ball and needle bearings support the spindle to reduce flex Cartridge design is easy to install, and comes without seals to minimise resistance Average Weight: 173gA 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.