torque sensor vs cadence sensor

Compare Torque Sensors vs. Cadence Sensors in Electric Bikes

There are two main types of sensors: torque sensors and cadence sensors. In this blog post, we will explain what torque and cadence sensors are, how they work, their advantages and disadvantages, and how to choose between them.

sempu torque sensor

What are Torque Sensors?


How does the Torque Sensor Work?

Torque sensors measure the amount of force or pressure you apply to the pedals when you pedal. They use strain gauges or other methods to detect the changes in the tension or deformation of the pedal axle or crank arm. Based on this information, they send a signal to the motor controller to adjust the level of assistance accordingly. The more force you apply to the pedals, the more power the motor delivers. 

 

Pros of Torque Sensors

Torque sensors provide a smooth, natural riding experience miming your pedaling effort. Torque sensors are usually more accurate and responsive than cadence sensors, as they can detect subtle changes in your pedaling force and react instantly. They also allow you to control the speed and intensity of your ride by varying your pedaling force.

 

Cons of Torque Sensors

However, torque sensors also have some drawbacks. They are usually more expensive and complex than cadence sensors, requiring more sophisticated technology and calibration. They may also be more prone to wear and tear or damage from external factors such as water, dust, or shocks. Moreover, some riders may find torque sensors too sensitive or unpredictable, as they may only sometimes match their desired level of assistance. For example, if you want to coast or relax on a flat road, you may have to reduce your pedaling force significantly to lower the motor assistance. Conversely, if you’re going to accelerate quickly or climb a steep hill, you may have to exert a lot of force to increase motor assistance.

 

Some examples of electric bikes that use torque sensors

  • Bosch Active Line Plus: This mid-drive system integrates a torque sensor into the bottom bracket. It offers four levels of assistance: Eco, Tour, Sport, and Turbo. It is designed for urban and recreational riding, with a maximum speed of 25 km/h and a maximum torque of 50 Nm.
  • Shimano STEPS E8000: This mid-drive system integrates a torque sensor into the bottom bracket. It offers three levels of assistance: Eco, Trail, and Boost. It is designed for mountain biking, with a maximum speed of 25 km/h and a maximum torque of 70 Nm.
  • Bafang BBS02: This motor can turn any regular bike into an electric bike. It uses a torque sensor attached to the pedal axle. It offers nine levels of assistance and has a throttle option. It has a maximum speed of 45 km/h and a maximum torque of 120 Nm.

cadence sensor

What are Cadence Sensors?


How Does Cadence Sensor Work?

Cadence sensors are magnetic sensors that detect the movement of the pedals on an electric bike and switch the motor on and off accordingly. They are usually located near the crankset or the bike’s bottom bracket, where they can sense the rotation of a magnet attached to one of the pedals. When the pedals move, the cadence sensor sends a signal to the controller, activating the motor at a preset power level. The motor’s power output depends on the selected pedal assist mode, which can range from low to high. The motor will continue to run as long as the pedals are moving and will stop when the pedals stop.

 

The main advantage of cadence sensors

The main advantage of using cadence sensors in electric bikes is that they are easy to use and require minimal effort from the rider. They are suitable for recreational riders or riders with physical limitations who want an effortless way to ride. They also provide consistent power and assistance at preset speeds, regardless of the terrain, gear ratio, or pedal speed. Cadence sensors can also allow riders to cruise and relax on their electric bikes or to pedal with lower assist settings for less assistance.

 

The main disadvantage of cadence sensors

The main disadvantage of using cadence sensors in electric bikes is that they are less responsive and accurate than torque sensors. They do not measure the actual force or pressure applied by the rider on the pedals, but only the movement of the pedals. This means that they cannot adjust the motor’s power output according to the rider’s needs or preferences. For example, if a rider wants to accelerate quickly or climb a steep hill, they may need to shift gears or increase their pedaling speed to get more assistance from the motor. Conversely, if riders want to slow down or coast, they may need to stop pedaling or reduce their speed to get less assistance from the motor. Cadence sensors can also cause a delay or a jerk in the motor activation, which can affect the smoothness and comfort of the ride.

 

Some examples of electric bikes that use cadence sensors:

  • Addmotor M-560 P7 750W Electric Mountain Bike
  • EZbike C1 500W Electric City Bike
  • KBO Breeze 500W Electric Commuter Bike

 

Torque Sensors vs. Cadence Sensors: Which One is Better?


In this section, we will compare torque and cadence sensors in terms of accuracy, efficiency, and overall performance and discuss the pros and cons of each sensor type. We will also provide some factors to consider when choosing torque and cadence sensors for your electric bike.

 

Torque sensors are sensors that measure the actual force or torque that the rider applies to the pedals. They are usually located in the bottom bracket, the rear hub, or the crank arm of the electric bike. Torque sensors are more accurate and responsive than cadence sensors, as they can detect the slightest changes in pedaling pressure and adjust the motor output accordingly. Torque sensors also allow for a more natural and smooth riding experience, as they mimic the feeling of a regular bike. The rider can control the level of assistance by pedaling harder or softer without changing gears or using a throttle.

 

Cadence sensors measure the rotational speed or cadence of the pedals. They are usually located on the electric bike’s chainring or crank arm. Cadence sensors are simpler and cheaper than torque sensors, as they only need to count the number of pedal revolutions per minute (RPM). Cadence sensors are less accurate and responsive than torque sensors, as they cannot detect the force or torque the rider applies to the pedals. Cadence sensors also provide a less natural and smooth riding experience, delivering a fixed amount of assistance based on the pedal speed. The rider has to change gears or use a throttle to control the level of assistance.

So which one is better: torque sensors or cadence sensors? The answer depends on your personal preference and riding style. 

 

Factors to consider between torque sensors and cadence sensors

 

The type of terrain you ride on 

Torque sensors are better suited for hilly or variable terrain, as they can adapt to the changing pedaling pressure and provide more consistent assistance. Cadence sensors are better suited for flat or steady terrain, as they can provide a constant boost based on the pedal speed.

 

The level of control

Torque sensors give you more control over the amount of assistance, as you can vary it by pedaling harder or softer. Cadence sensors give you less control over the amount of assistance, as you have to rely on gears or throttle to vary it.

 

The level of realism

Torque sensors offer a more realistic and natural riding experience, as they simulate the feeling of a regular bike. Cadence sensors offer a less realistic and natural riding experience, delivering a fixed amount of assistance regardless of pedaling pressure.

 

The level of maintenance

Torque sensors require more maintenance than cadence sensors, as they are more complex and sensitive to wear and tear. Cadence sensors require less maintenance than torque sensors, which are simpler and more durable.

 

Final Thoughts on Torque Sensor vs. Cadence Sensor


Both torque sensors and cadence sensors have their advantages and disadvantages when it comes to electric bikes. Torque sensors offer a more natural and responsive riding experience, while cadence sensors provide a more effortless way of riding. The choice between them ultimately depends on your personal preferences and the type of terrain you ride on. Consider the factors mentioned above when choosing between these two types of sensors to make the most out of your electric bike.

henry
Marketing and Sales Manager at Jieli Electric | Website

Sales Manager at Jieli Electric Bikes.
Near 10 years experience in electric bike industry, researching/marketing/promoting e-bike is my daily life.

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