1.0 metric pitch Traxxas spur gear Spur gear, 38-tooth (1.0 metric pitch) Optional Traxxas spur gears allow you to increase or decrease the final drive ratio and tune for different applications. Smaller gears will increase the speed of the vehicle while larger gears will increase the torque. Use Traxxas stock and hop-up replacement parts to get the most out of your Traxxas RTR vehicles