When it comes to bang for the buck, Shimano's Zee components like this 83mm bottom bracket compatible Zee FC M645 Crankset are hard to beat. Thick walled aluminum construction with a reinforced steel axle ensures flex and failure are absent from gravity fueled runs. These two piece cranks are 10 speed only and come with a 36t chainring. For added durability, Shimano gives the Zee cranks steel pedal inserts. The drive side arm has a 104mm BCD, and it uses alloy chainring bolts. Shimano's Zee FC M645 does not include a bottom bracket, and it comes in three lengths: 165, 170, and 175mm.