Gearbox Motor QSJ128B-70 mid-drive motor, a high-performance PMSM unit tailor-made for high-speed electric motorcycles, modified EV bikes and performance two-wheelers.
Adopting advanced hairpin winding technology and built-in reduction gearbox plus encoder sensor, this 4500W mid drive motor delivers outstanding torque, ultra-high efficiency and reliable regenerative braking capability to upgrade your electric vehicle power system completely.
Core Competitive Advantages
1. Compact & Lightweight Mid-drive Design
Compared with traditional heavy hub motors, the QSJ128B-70 mid drive motor features a smaller overall outline and lighter weight (only 9.98kg).
It reduces unsprung weight of wheels, optimizes vehicle handling, and supports universal installation for most electric motorcycle frames with easy modification.
2. Strong Power & Excellent Acceleration & Climbing Performance
Equipped with permanent magnet synchronous motor structure and flux weakening control technology:
– Rated power: 4.5kW, peak maximum output power reaches 10.5kW
– Pre-reduction max torque up to 67N·m, paired with 3.462 reduction ratio for explosive climbing force and instant throttle acceleration
– Stable output under heavy load, perfect for mountain roads, high-speed commuting and performance riding scenarios
3. Ultra-High Energy Efficiency & Regenerative Braking
Peak efficiency of the motor exceeds 95%. It maintains low energy consumption during long-distance riding and uphill driving, greatly extending battery range.
It fully supports regenerative braking function, which recovers kinetic energy while decelerating to further save power and improve endurance.
4. Stable & Durable Industrial-Grade Construction
– IP67 full waterproof rating, resistant to rain splashes, road mud and daily car washing, suitable for all-weather riding
– Natural cooling structure with Class H high-temperature resistant insulation, winding withstands working temperature up to 150°C
– Built-in KTY83-122 thermistor (optional) for real-time temperature monitoring to prevent overheating damage
– Encoder sensor version ensures precise speed signal transmission, compatible with CAN bus smart dashboards
Why Choose QSJ128B-70 Mid Drive Gearbox Motor?
– Hairpin winding mid-drive structure, lighter and smaller than hub motors, better vehicle balance
– Up to 10.5kW peak power + 67N·m raw torque, strong climbing and fast acceleration
– Over 95% peak efficiency with regenerative braking, longer battery mileage
– IP67 waterproof & wide temperature resistance, stable for global tropical and rainy markets
– Encoder sensor compatible with CAN BUS smart dashboards, complete vehicle intelligent linkage
– Complete technical drawings, test performance charts and operation manuals provided for OEM & aftermarket dealers
For bulk OEM customization, technical drawings, test reports and wholesale quotations, kindly reach out to our professional sales team for full support.
