QS 138 70H V3 for Electric ATV Dirt bike and Motorcycle For QS138 70H V3 mid drive motor with 1:2.35 gear box, it could be used for electric dirtbike, electric motorcycle, electric ATV 72V 100-105KPH with high torque. Compare with QS138 V1 and V2 motor, it's integrated with 1:2.35 gear box, which save space for double step transmission, with more torque.