The Shimano ALFINE is a top component group for sporty and elegant cycling. Premium quality, style, adaptability and easy handling are the characteristics of the Shimano Alfine. The tidy appearance and the large gear ratio of this eight-speed hub gear system gives the bike a real tailwind. The Shimano Alfine FC-S501 comes with SM-BB4600 bottom bracket.2-Piece DesignIntegration of crank arm and bottom bracket: Increased stiffness with less weight. The axle bearings are positioned further apart: stiffness is increased and the rider's power is effectively transmitted. Precision bearings: low maintenance and simplified assembly. - Purpose: City - Details: - Anodized and painted crank arms, anodized chainring - Anodized aluminum chain guard ring (outside) - Diameter of chain guard ring 190 mm (42 t.) - Not compatible with chain case - Material specifications: Aluminium scope of delivery - Scope of delivery: 1 x crank set Shimano Alfine FC-S501 (39 teeth), 1 x chain guard ring Shimano, 1 x bottom bracket Shimano SM-BB4600, 1 x crank chainrings - Number of chainrings: 1 chainring - Gear ratio: 39 teeth crank - Compatibility rear derailleur: 8-speed - Type: 5-arm - Axle mount: 24mm - Pitch circle: 130 mm - Pitch circle type: Standard - Chainline: 42.8 mm - Crank arm length: 170 mm Chain guard - Chain guard ring