Torque Sensors vs. Cadence Sensors: Which eBike Pedal Assist Is Better?

How Pedal Assist Works

The pedal assist on an ebike is engaged when the rider pedals and disengaged when the rider stops pedaling. There are two types of sensors that perform this action: cadence sensors and torque sensors. A cadence sensor measures movement of the pedals while a torque sensor measures pressure exerted on the pedals. There are benefits to both sensor types however, they feel and act very differently.

Cadence Sensors

Cadence sensors are the original method utilized for pedal assist input on ebikes. The sensors are basically an on/off switch that are triggered by the movement of the cranks on the bike. The ebike’s motor is engaged when the rider begins to pedal forward, usually after a ¼ of the crank revolution has been reached, and turned off when the rider stops pedaling.

The benefit of using a cadence sensor is the relatively light pressure needed to employ it. This means riders can get lots of steady motor assist with very little effort, which benefits anyone who has limited pedaling ability or strength.

The other benefit of the cadence sensor is its low cost and simple design. Often hub drive bicycles are paired with cadence sensors, although that is not always the case.

Torque Sensors

Torque sensors are newer to the ebike industry and often synonymous with mid drive motors, although there are hub driven bikes with torque sensors as well as mid drive motors that are cadence sensor-based.

A torque sensor measures how much pressure the rider is putting into the pedals and provides assistance proportional to the force applied. This works by using a strain gauge to measure pedal pressure many times per second and has nothing to do with actual crank motion.

This provides faster and smoother assist engagement as well as a more conventional bicycle pedal feel. In short, when the rider pedals hard, the motor outputs more power up to the predetermined limit for a given PAS level, and when the rider eases off the pedals the motor provides less motor assist.

This eliminates the ghost pedaling feel and improves the efficiency of the motor (think more range).

Who Benefits From Cadence Sensors

For riders who desire lots of unwavering motor assist in order to travel as fast as possible or work as little as possible, a cadence-based ebike is the better choice.

These types of ebikes are typically “faster” and feel more powerful. The downside is the assist takes a second to engage, and once it does, the engagement is more abrupt and louder.

In order to make the motor assist stop, the rider has to stop pedaling entirely, and then the assist turns off abruptly. Often cadence based systems are described as less smooth, but they will feel more powerful than a torque based system even if they have the same wattage and torque rating.

Who Benefits From Torque Sensors

If a rider desires an intuitive pedal feel because they want to ride a bicycle (with assist) a torque sensor is the better choice.

The assist will come on and ease off in a smooth fashion, mimicking the rider's pedal habits closely. A rider can pedal lightly without triggering a lot or any motor assist, which benefits anyone riding technical terrain or narrow/windy situations.

A torque-based system will require the rider to input more effort in order to get motor assist, so in general, riders will “feel” like the system is less powerful. Torque sensors are more complicated and expensive, but they do improve motor efficiency and range.

Conclusion

Both cadence and torque sensors offer unique advantages that cater to different types of riders and riding styles. Understanding how each system engages the motor and affects the feel of the ride can help riders choose the ebike setup that best matches their needs. Whether someone wants maximum assist with minimal effort or a more natural, intuitive pedaling experience, knowing the difference between these sensor types ensures they can make a more informed decision and enjoy a ride that aligns with their preferences.