A Hybrid Electric Motorcycle (HEM) with a variable-winding brushed DC wheel motor is proposed in this paper. When the windings are connected in parallel, the motor has wide speed range suitable for high-speed cruising. When the windings are connected in series, the motor can provide high starting torque and thus reduce the necessary engine size for the proposed HEM. The optimal upper and lower power limits of the engine operating region are obtained from the optimal design theory. A dynamic simulation model is established in Matlab/Simulink to evaluate the performance of the proposed HEM and traditional motorcycles using the ECE40 driving cycle.