Renthal grooved off road front chainwheels are designed to offer excellent durability with a lightweight design which delivers maximum power transfer. Each sprocket is CNC machined from cased hardened and core refined 655M13 nickel chromium steel. Mud grooves are then CNC machined into each tooth on both sides to allow mud to flow away from the key contact points between the chain and the sprocket. This unique design helps reduce wear and dramatically increases the lifespan of your drivetrain.