• 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