Torque Sensors vs. Cadence Sensors on Electric Bikes

Benefits of a cadence sensor

Cadence sensors offer some terrific benefits. The biggest one is likely to appeal to people who haven’t ridden a bike in a while. With a cadence sensor, the rider’s speed is largely determined by the PAS level the rider has selected. Again, a cadence sensor doesn’t care how hard the rider is working.

An e-bike with a cadence sensor is ideal for the rider who wants/needs the e-bike to do the heavy lifting. Whether someone is recovering from an injury or working long hours, a cadence sensor means the e-bike will deliver even if the rider’s legs won’t. One neat little trick that’s possible with e-bikes using cadence sensors is a phenomenon called ghost pedaling. As long as the pedals are turning, the cadence sensor will tell the motor to go; a rider doesn’t need to pedal hard enough to feel pressure on the chain. For riders looking for some activity, but wanting to avoid anything strenuous, an e-bike with a cadence sensor is ideal.

Drawbacks of a cadence sensor

The most noticeable drawback to a cadence sensor is that motor engagement is delayed. Needing to complete half to most of a pedal stroke before the motor starts means that the rider will always be forced to start with no assistance, and starting is often one of the more strenuous parts of riding; we can’t always roll from the top of a hill. That delay can be annoying. And for anyone carrying a load, that means getting going will require even more work.

Because a cadence sensor will instruct the motor to do most of the work of moving, e-bikes with cadence sensors aren’t as frugal with their battery use. As a result, e-bikes with cadence sensors don’t have as much range as e-bikes with torque sensors, when we compare e-bikes with the same size batteries.

Another drawback to a cadence sensor is that for the rider looking to burn calories and build fitness, the presence of a cadence sensor can cause someone to overestimate just how hard they are working. For the person with specific fitness goals, they will need another way to receive feedback on how hard they are working, like a fitness tracker or heart rate monitor.

Benefits of a torque sensor

For anyone who has ridden an e-bike with a cadence sensor and then tried one with a torque sensor, the first thing they notice is that power is available the very moment the pedals start turning. The zoom starts immediately. The second thing a rider will notice (like, a second later) is that as they begin to pedal harder, the motor adds more zoom.

We sometimes talk about the feeling of having bionic legs when riding an e-bike with a torque sensor; it’s a truly remarkable sensation because we have the sense that the motor is reading our mind. When we pedal harder, the motor delivers more power and when we go easier the motor reduces its output. It’s this part of the torque sensor experience that results in what many riders call a seamless experience as it becomes harder to differentiate between our output and the motor’s output.

E-bikes with torque sensors are ideal for riders who already have a reasonable amount of fitness, or plan to work hard to build their fitness. These e-bikes are for people who enjoy pedaling and don’t mind sweating in exertion.

Because their motor output varies and divides the work with their rider, e-bikes with torque sensors typically see greater range than those equipped with cadence sensors and the same size batteries.

Drawbacks of a torque sensor

Pedaling an e-bike with a torque sensor is work. For people returning to riding after an injury or years of sedentary work, that can curtail ride length due to a lack of endurance.

There’s good news on this front, though. E-bikes with both torque sensors and hub motors usually also include a throttle (these are less common on e-bikes with mid-drive motors). Riders concerned about their legs growing fatigued can think of the throttle as an insurance plan. Even if they overestimate how much their legs can handle, the throttle will get them home (so long as there’s enough juice left in the battery).

Another aspect of torque sensors that some riders might object to is that – until they have some experience pedaling at a consistent effort – each change in effort will cause the motor to surge or relax and not everyone enjoys such constant changes in pace. We’re talking minor changes if someone is pedaling steadily, but the higher the PAS level selected, the more noticeable the surging with each pedal stroke will be.

Is a torque or cadence sensor best for you?

The differences between an e-bike with a cadence sensor and one with a torque sensor are both noticeable and helpful to different types of riders. Just as there is no one perfect bike for all riders, the differences between a torque sensor and a cadence sensor aren’t a matter of better or worse, but a matter of which fits better for the sort of riding someone wishes to enjoy. You’ll find both on the best electric bikes out there!

As with anything involving shopping for an e-bike, shoppers should spend some time thinking about what sort of riding they wish to do—where they want to go, if they will be in a hurry to get there, how hard they are willing to work and how seamless an experience they want.

Prospective e-bike owners should also get out for some test rides if possible. There’s no education like feeling the difference between the two experiences, although we do our best to describe them in our e-bike reviews.

As with most things in life, we can be reassured by knowing there are choices and that those choices can lead to a better experience.