The Vision Track Crank features oversized solid forged aero arms optimized for rigidity and a deep-tooth 49T chainring, as well as an ultra-stiff 30mm spindle. The 386EVO spindle design assures compatibility with all major bottom bracket shells.Solid forged alloy 6061. Forged 7050 30mm spindle. Polished anodized black with laser graphics. Item Specifications: Pedal Spindle: 9/16", BB Included: No, Chainring BCD: 144, Color: Black, Crank Intended Use: Track, Number of Chainrings: Single, Crank Length (mm): 165 mm, Rings: 49, Drivetrain Speeds: Single Speed 1/2" x 1/8", Spindle Interface Type: 386 EVO, Chainline/Hub Compatibility: 120 Hubs,