High-Torque Mid-Drive Motor

The High-Torque Mid-Drive Motor is a core powertrain system designed for high-performance electric mountain bikes, off-road e-bikes, heavy-duty utility vehicles, and long-range power conversion projects. Manufactured by Qianjiang Motor, it offers comprehensive one-stop OEM/ODM solutions.

What is the High-Torque Mid-Drive Motor?

This motor utilizes a permanent-magnet brushless geared structure combined with a high-precision torque-sensing algorithm. Power output adapts linearly to pedaling effort, balancing smooth assistance with explosive power delivery.

With the center of gravity concentrated in the middle of the frame, the vehicle offers superior stability and agile handling. It eliminates common issues such as sluggish climbing, front-end instability, excessive unsprung weight, and instability at high speeds, making it the ideal power solution for premium personal transport, off-road riding, mountainous terrain, and heavy-duty commuting.

The lineup covers a power range from 350W to 4500W with peak torque reaching 70–100Nm. It supports wide-voltage compatibility (48V/60V/72V), making it suitable for a full spectrum of applications, from consumer-grade e-bikes to high-performance off-road electric motorcycles.

Product Advantages

1. High-Torque

The motor features an integrated precision gear reduction assembly. By utilizing mechanical gear reduction to multiply torque, it significantly boosts starting torque at low speeds.

It ensures robust, responsive performance without stalling or sluggishness; it provides solid traction for starts, even under heavy loads, without wheel slip. It is ideal for high-demand riding scenarios such as steep inclines, carrying passengers or cargo, and off-road traversing.

2. Centered Frame Layout

The mid-drive motor is mounted at the frame's bottom bracket, centering the vehicle's gravity. This design allows for lighter wheelsets with lower rotational inertia.

It ensures stability at high speeds, steadier cornering, and agile steering. It offers superior tracking on bumpy off-road terrain, balancing the needs of daily commuting with high-intensity athletic riding.

3. Integrated Gear Shifting

Power is delivered via a chain drive, making it compatible with standard cassettes, derailleurs, and shifting groupsets. Riders can adjust power and speed by changing gears.

Low gears amplify torque for climbing, while high gears boost top-speed cruising. This staged power delivery is smarter, more efficient, and more energy-saving than the single-speed mode of hub motors.

4. Intelligent Torque Sensing

The motor is equipped with a high-precision torque sensing system that detects pedaling force and cadence in real-time, dynamically adjusting power output. It reduces rider fatigue during long rides, making it perfect for long-distance commuting.

5. Universal Wheelset Compatibility

The mid-drive system does not rely on proprietary wheelsets. It supports a wide range of standard 16–29 inch wheels, including tubeless and aggressive off-road tires. Riders can freely switch between mountain, road, and puncture-resistant tires, as well as upgrade wheel sizes and configurations.

6. Split-Drive Structure

The motor is mounted independently, utilizing a separate chain drive. Impacts from bumps and resistance from overloads are absorbed and buffered by the chain, significantly protecting the motor unit itself.

Maintenance is limited to the chain and chainring; the motor unit requires no frequent maintenance over its lifespan, offering superior long-term value.

7. All-Scenario Durability

The motor housing features heat-dissipation fins that rapidly dissipate heat during high-power, prolonged climbing, thereby reducing the risk of high-temperature demagnetization and coil degradation. The unit features a fully sealed, dustproof, and waterproof design capable of handling complex outdoor conditions, including rain, mud, and gravel, ensuring superior durability for off-road riding and mountain commuting.

Product Specifications

Suitable Applications

● Professional power upgrades and modifications for electric mountain bikes and off-road bicycles

● Daily commuting, passenger transport, and heavy-load riding in mountainous areas or on steep terrain

● Long-distance outdoor riding, cross-country touring, and endurance cycling

● High-performance electric scooters and low-speed power systems for specialized equipment

● High-end users seeking stable handling, smooth pedal assistance, and superior climbing capability

FAQ

Q: What is the difference between a mid-drive motor and a hub motor?

A: Hub motors drive the wheel directly; they feature a simple structure and are inexpensive to retrofit, but they offer limited torque, weak hill-climbing ability, increased unsprung weight (heavy wheel assembly), and instability at high speeds.

High-torque mid-drive motors utilize gear reduction and integrate with the gear-shifting system. They deliver higher torque, superior hill-climbing performance, a stable center of gravity, precise handling, and variable gearing to adapt to all road conditions.

Recommendation: Choose a hub motor for simple commuting on flat roads. Prioritize a high-torque mid-drive motor for hilly terrain, heavy loads, off-road riding, long-distance trips, or if you value a premium riding experience.

Q: Must a high-torque mid-drive motor be used with gear shifting?

A: You can ride normally without shifting gears, but you won't be able to utilize the motor's full performance potential.

Its core advantage lies in adapting gears to riding conditions: shifting up for high-speed cruising on straight roads, downshifting for increased torque on steep slopes, and maintaining stability at low speeds with heavy loads.

Riding in a fixed gear wastes the torque advantage and can cause overheating during prolonged, high-load operation. We recommend adjusting gears in real-time based on road conditions to optimize both power delivery and range.

Q: Mid-drive motors are powerful on hills; why do I hear a slight noise when riding slowly with a heavy load?

A: This is normal behavior for a gear-reduction motor. During high-torque output, the load on the internal precision gear mesh increases, resulting in a faint mechanical meshing sound. This is a normal sound associated with power transmission and does not affect the motor's lifespan or performance.

However, if you hear a sharp whistling sound, grinding/stuttering noises, or experience power interruption, it may indicate an improperly tensioned chain, lack of gear lubrication, or drivetrain misalignment; prompt inspection and adjustment are required.

Q: What are the key points for daily maintenance?

A: The motor unit itself features a maintenance-free, sealed design; there is no need to disassemble it for lubrication or replace carbon brushes.

Daily maintenance should focus on the drivetrain: regularly clean and lubricate the chain, check the chainring for wear, and adjust chain tension. Avoid letting the chain become too loose (which causes skipping) or too tight (which creates excessive load).

Avoid prolonged immersion of the motor's central axle and cable exit point in deep water to ensure long-term, stable operation.

Q: How well does the motor withstand vibration and shocks?

A: The unit is rigidly mounted to the frame's bottom bracket area, ensuring a stable structure; compared to hub motors, which feature a suspended, wheel-end design, this setup offers superior resistance to bumps and impacts.

Impact forces from rough off-road terrain are absorbed by the frame and chain, protecting the motor body from damage; the failure rate due to vibration is significantly lower than that of hub motors, making it ideal for long-term use in challenging outdoor conditions.