Mountain Bike Aluminum Alloy Crankset Integral Single Speed Sprocket (Black Crank+Bottom Brack) $ 68.99 Features: Made of premium aluminium alloy, which is lightweight, adding no heaviness to bike. High strength and deformation resistance, durable for long time use. Standard precision machining, which ensures ultimate chain retention, increases service life, and reduces friction and noise. 170mm crank arm length without any overlap of crank arm and chain ring bolt. An ideal replacement for bike repair, compatible with many bike models. Specification: Material: Aluminium Alloy Color Options: Black;Red; Silver BCD: 104 mm Arm Length: 170 mm Weight: Approx. 675 g Package Included: Show as picture