E-Bike Info: Torque Sensor vs. Cadence Sensor

So you think you want an e-bike? Awesome! There's a lot of information to wade through, and a lot of advancements are being made in the e-bike world every day. Here, we hope to help you get a grasp of some of the technology that goes into these bikes and help you make a better-informed decision when it comes time to purchase. 

By now, you've probably seen a few brands mention something on the bike called a torque sensor or a cadence sensor. We're going to go through what both of these are, how they work, and what that means in terms of the overall feel of riding the bike. 

TORQUE SENSOR

A torque sensor in an electric bike is a component that measures the amount of force or rotational effort applied to the pedals by the rider. It plays a key role in the bike's pedal-assist system, which is the whole point of an e-bike! 

Here's how it generally works:

• Location and Integration: The torque sensor is typically integrated into the bike's bottom bracket, which is the part of the frame where the pedals are attached. Alternatively, it can be integrated into the rear dropout or other parts of the drivetrain.

All of the models with a torque sensor that Battlefield Outdoors sells have the torque sensor in the bottom bracket shell. 

• Sensitivity to Pedal Force: The torque sensor is designed to be sensitive to the force exerted on the pedals. As the rider pedals, the sensor measures the amount of force or torque applied during each pedal stroke.

The torque sensor generates an electrical signal proportional to the force applied. This signal is then transmitted to the bike's controller or motor system.

• Pedal-Assist Control: The controller uses the torque information to determine how much assistance the electric motor should provide. The more force the rider applies to the pedals, the more assistance the motor provides. This ensures a smooth and natural feeling of assistance, making the e-bike more efficient and responsive to the rider's input.

• Efficiency and Battery Conservation: By responding to the rider's effort, the torque sensor helps optimize the energy usage of the electric motor. When the rider is pedaling with more force, the motor provides more assistance, and vice versa. This not only enhances the riding experience but also contributes to better energy efficiency and battery conservation.

Cadence Sensor

In contrast, cadence sensors consist of a magnet ring that fits under the crank arms, usually on the non-drive (left) side of the bike. Cadence sensors only measure how fast the pedals are turning. Since they operate by sensing the crank arm as it passes the magnet, cadence sensors lend a very on/off feel to the pedal assist system. Once the sensor detects movement, it fully engages the motor at whatever assist lever the system is set on. 

Cadence vs. Torque

What does this mean for the real-world feel of the bike?

Since torque sensors operate on direct pressure input from the rider, this leads to a more natural and intuitive riding experience, resembling the feeling of riding a traditional bicycle while enjoying the benefits of electric assistance when needed.

The "jump" of the pedal assist system engaging with the cadence sensor can be startling for some riders. However, if you prefer instant motor response, as a few of our staff members do, a cadence sensor may be a good choice for you. 

Either way, we hope that this was a clear comparison of the differences between the two e-bike assist systems. 

As always, if you have any other questions or want to test ride an e-bike with each sensor type, stop by and see us! 

Now go ride your bike!