Shimano Dura-Ace Track BB-7700 Bottom Bracket Italian-threaded 70×109.5mm (M36)
・Thread Size: M36. ・Compatible with Shimano Octalink cranksets only. ・Hollow spindle design for reduced weight. This version is designed for Italian-threaded (ITA) bottom bracket shells with a 70mm shell width and a 109.5mm spindle length.