The Shimano 105 5500 Bottom Bracket comes with an Octalink splined axle/crankarm interface in either 109mm or 118mm lengths and is designed for use with the Shimano Road Octalink crankset. The oversize BB spindle has a large, 22mm-diameter, chrome-moly hollow pipe billet spindle to reduce weight and increase strength and rigidity, and the Octalink splined axle/crank arm results in a more rigid crank assembly compared to a square tapered spindle. The maintenance-free sealed cartridge design prevents corrosion and is easy to install. Aluminium adapter included. Italian thread. Average weight 250g.