NOV5909 - Ideal tuning rotor for Touring Car, Oval, 1/12th-scale or other high-traction applications. The Novak Sintered 13mm Tuning Rotor was designed to alter the feel and experience of driving a Novak motor, and offers a new dimension of tunability. With a slightly larger diameter and improved magnetic material, the rotor can withstand a higher temperature threshold, improving its durability. It also increases the natural drag brake and opens up the motor's gearing window to improve drivability. The Sintered 13mm Tuning Rotor is compatible with the Novak Velociti-series, SS Pro-series, and other Novak 540-size brushless motors that have an oversized front bearing.