The Alfine chainset is a light weight sleek 2-piece design using the proven external bottom bracket system
2-piece design is both lightweight and stiff for optimum power transfer
Built in single sided chain guard
170 mm crank arm length
Chainring is for use with 9-speed chains  and CS-S500 rear sprocket
BS thread bottom bracket included for 42.7 mm chain line
5-arm 130 PCD