How does an electric bike work?
The electric bike has revolutionized the way we think about urban mobility and leisure cycling. Unlike an electric scooter, an electric bike remains a bicycle: it requires the rider to pedal in order to move forward, but it greatly amplifies the cyclist’s effort. In this article, we will take a detailed look at how an electric bike works.
Key takeways:
- The motor only activates while pedaling and is controlled by cadence or torque sensors, providing a more or less smooth riding experience.
- The controller transfers energy from the bike battery to the motor. The motor can be located in the wheel or in the crankset.
- Proper use of assistance modes and correct gear shifting are essential to optimize battery range and lifespan.
Pedal assistance: the principle behind an electric bike
The way an electric bike works is based on pedal assistance. Unlike a combustion engine that runs independently, the motor of an electric bike only activates when it detects movement of the pedals. This interaction is managed by two types of sensors:
The cadence sensor: It simply detects whether the pedals are turning. It is a binary system: when you pedal, the assistance starts. Bikes equipped with this sensor are generally more affordable and easier to use. However, the lack of responsiveness can make the ride feel less smooth.
The torque sensor: More advanced, it measures the actual force you apply to the pedals. If you push hard, the motor delivers more power. If you pedal lightly, the assistance remains subtle. A torque sensor is more expensive, but it makes pedaling much smoother and more natural. It also helps improve your battery range.
This system is managed by a controller, the true brain of the bike, which draws energy from the bike’s battery (usually lithium-ion) to power the motor.
How does the motor transmission work?
The point where the motor delivers its power changes the way the bike behaves. There are two main types of transmission:
Hub motor: Located in either the rear or front wheel, this is a simple system that is often more affordable and ideal for city riding. However, it does not benefit from the bike’s gears and can make tire changes more complicated.
Mid-drive motor: This is the most advanced technology. The motor is positioned directly at the crank axle. Its main advantage is that it benefits from the bike’s mechanical transmission through the chain and derailleur. Just like in a car, the motor takes advantage of the gear ratios: a small sprocket is used for speed, while a larger sprocket provides more torque when climbing. This offers a natural balance and optimal energy efficiency.
How to use your electric bike
Managing assistance modes
On the handlebar, a display with buttons allows you to choose the level of assistance (Eco, Tour, Sport, Turbo, etc.). To preserve the battery, it is recommended to stay in Eco mode on flat terrain and only use more powerful modes when truly necessary (headwinds, hills, and so on).
Shifting gears
This is the classic beginner’s mistake. You still need to shift mechanical gears just as you would on a regular bike. Climbing a hill in a high gear while relying only on the motor will make the motor overheat and drain the battery prematurely.
Properly maintaining your bike and battery
An electric bike is subjected to more mechanical stress than a standard bicycle. The bike battery in particular requires regular maintenance. The chain, sprockets, and brake pads may wear out faster because of the additional weight and motor power. We recommend checking your bike’s condition regularly. Do not hesitate to contact your dealer if needed.
To learn more and find out how to use your electric bike properly, check out our complete guide.
