Provides the toothed gear that mounts on the motor shaft and meshes with the spur gear to transfer power into the drivetrain. Designed for a 21‑tooth configuration to influence acceleration and top speed characteristics on compatible RC models. Constructed from durable metal to withstand rotational forces and repeated use under load. Helps maintain proper gear engagement and smooth power delivery for consistent performance. Suitable for replacing worn or incorrect pinion gears to tune drivetrain behavior.