How does an electric bike work?

An electric bike has a motor that helps as long as you pedal. A sensor detects that you are pedaling, the battery supplies power, and the motor gives you a push. In the Netherlands, that pedal assistance stops at 25 kilometers per hour, and the motor has a maximum nominal power of 250 watts. If you stop pedaling, the assistance stops too.

Below, you can read what the components do, how the motor knows you are pedaling, and how to choose how much assistance you receive. You will also read why a fatbike is an electric bike too. At the bottom, you will find e-bikes with the motor and battery specified by the manufacturer for each model.

What components does an electric bike have?

An e-bike includes, among others, these components that a regular bike does not have:

• The battery. This is where the energy is stored, and its capacity is shown in watt-hours (Wh).
• The motor. It is located in the front wheel, rear wheel, or in the center near the bottom bracket.
• The sensor. It detects that you are pedaling, and on some bikes also how hard.
• The handlebar controls. These allow you to choose how much assistance you want.

Bosch describes it as follows: the motor provides extra assistance depending on your effort, your speed, and the assistance level you choose. You charge the battery with the accompanying charger. Once it is full, unplug it, advises the fire service.

How does the motor know you are pedaling?

Through a sensor. There are two types.

A rotation sensor only detects that you are pedaling, not how hard. As soon as you pedal, the motor helps, even if you apply hardly any force. According to the Fietsersbond, it starts and stops with a slight delay, and the assistance can engage fully when you rotate the pedals without load, for example while turning around. Keep this in mind in a tight turn.

A torque sensor also measures how hard you pedal. The harder you pedal, the more the bike assists, writes ANWB, which feels more natural. Most mid-drive motors have a torque sensor, while most fatbikes have a rotation sensor, according to the Consumers' Association.

How do you choose how much the motor assists?

Use the buttons on your handlebar to choose an assistance level. Most systems have at least two, writes Shimano: an eco mode that saves power because you do most of the work, and a mode with more assistance. The display often shows which mode is active, how fast you are going, and how far you have ridden.

With a torque sensor, the rule is: the higher the level, the more power the motor delivers, but the shorter the distance you can travel on a full battery (Consumers' Association). With a rotation sensor, the levels often work differently. In that case, you choose the speed up to which the motor assists, for example up to 18 or 25 km/h. How you turn on the bike and which buttons it has varies by model, so check the manual for details.

Why does the assistance stop at 25 km/h?

Because that is what the law stipulates. Under the Road Traffic Act, a bicycle with pedal assistance has an auxiliary motor with a maximum nominal continuous power of 0.25 kW, or 250 watts. The assistance must decrease gradually and stop at 25 km/h, or earlier if you stop pedaling. You can go faster, but under your own power.

Pay attention to the word nominal: the limit concerns nominal, continuous power. A motor's maximum power may be higher; Bosch lists this separately for its motors. A throttle that lets you go faster than 6 km/h without pedaling legally makes your bike a speed pedelec, moped, or low-speed moped (Government of the Netherlands). However, a bike may have a walking assist function that helps you up to 6 km/h when you walk alongside it (RDW).

Is a fatbike also an electric bike?

Yes. According to the Government of the Netherlands, a fatbike is an electric bike with wide tires; an electric cargo bike is also an electric bike. If a fatbike provides pedal assistance up to a maximum of 25 km/h and has a motor with a maximum nominal power of 250 watts, the rules for an electric bike apply. If it can go faster than 25 km/h with continued pedaling, it must be approved as, for example, a moped, low-speed moped, or speed pedelec. Its operation is otherwise the same: motor, battery, sensor, and controls. You can find models among the fatbikes.

What is the difference from a speed pedelec?

E-bike and electric bike are two words for the same thing; the Government of the Netherlands places e-bike in parentheses after electric bike. A speed pedelec is different. It provides pedal assistance up to 45 km/h, may have a motor of up to 4,000 watts, and is legally classified as a moped. Among other things, you need a helmet, a yellow license plate, a moped license, and third-party liability insurance (RDW).