Precision engineered Dura-Ace 7700 Bottom bracket for road Octalink splined system22 mm diameter chrome-moly hollow pipe billet axle reduces weightSplined interface provides a more rigid crank assembly compared to tapered counterpartsCompound bearing structure - ball and needle bearings support the spindle to reduce flexMaintenance-free sealed cartridge design prevents corrosion and is easy to installAverage weight 173 grams