How Does An Electric Bike Speed Controller Work?

The e-bike speed controller is the most crucial component of an e-bike. It’s an electronic circuit that controls the speed of a motor along with serving as a dynamic brake.

The speed controller uses power from the e-bike battery and drives to the motor hub. It can be varied in type as it is controlled by different types of motors. To provide you with a clear concept of how an e-bike speed controller works, we’ve briefly described the components involved with the functioning of an e-bike’s speed controller.

How Does An Electric Bike Speed Controller Work?

electric speed controller

Ebike’s speed controller assists you to shift your riding mode to manual paddling and electric driving. Thus, it helps to reduce your physical effort in riding and makes it easy to climb hilly areas smoothly.

The speed controller remains attached to the rear wheel of an e-bike which may restrict your speed limit as it is pre-programmed to stop the motor from working once you reach the programmed limitation. If you don’t want the speed controller to restrict your riding speed you may remove the speed limiter on an electric bike. But you have to be careful while riding otherwise for riding without any limitation you may break the rule of your respective country or get in an accident.

Speed Controller

There are different types of speed controllers that may vary depending on the type of motor. That’s why it’s crucial to choose a matched motor-powered voltage for the battery pack. For example, A 24v controller with 6 batteries can drive a 36v motor but the motor’s speed limit won’t cross its climbed output watt powers.

A controller runs at a lower rated voltage than the battery and motors are responsible for burnout or overheating of the connector. Before knowing the working method of an E-bike controller let’s know the basics about it.

The speed controller and the motor type should match otherwise its functions won’t work. For instance, a brushless motor controller needs a brushless motor. Some controllers need only a Hall-sensor motor and the other controllers work without any sensors. Switching to a reluctant motor is much more effective while a complex wave controller is used in the conjunction. This type of brushless controller may cost you more but you will get smooth acceleration from it.

Brushed Motor Controller

The speed of a brushed DC motor depends on the input voltage and is controlled by a rheostat that’s why it’s not necessary to use a controller. Most often the efficiency of a brushed motor is very low and e-bike can’t get in the range that usually 36v to 48v batteries may deliver. That’s why the e-bike manufacturer has switched to the brushless motors.

Brushless Motor Controller

Most e-bikes use brushless DC motors which require brushless motor controllers. These controllers may rely on internal sensors of the motor to determine the operating speed as feedback in the power cord.

Sensor Or Sensorless Controller

If your e-bike conversion kit includes a Hall sensor, you can use a Sensored or Sensorless speed controller. Moreover, If your bike’s motor is sensorless, you have to use a brushless motor controller which accepts sensorless operation. Before using any controller check the product description of your e-bike.

The Direct Drive Motor And Gear Motor

A direct drive motor may need higher current controllers compared to a gear motor that provides similar peak output watts. That’s how a direct drive motor uses high starting torque. A higher ampere peak controller is needed to protect the controller from getting damaged. On the other hand, geared motors may run at a higher voltage.

Voltage And Current

For a proper match with the e-bike motor speed controller, you can use a brushless motor and make sure that it can meet the continuous power and amp requirements of the motor and power system. Suppose, a 36v and 500w peak motor needed a 14 amp capacity controller.

Supplementary Motor Speed Controller Options

The latest e-bike motor speed control system can realize precise speed control and clamor noise. The sine wave e-bikes controller provides a smooth start and decreases torque pulsation.

Variable Assist

You may know that a 36v, 500w e-bike motor controller has connectors for the speed sensor wires and throttle which assists in smooth acceleration and multiple pedal assist modes.

If you like to have display options to see the voltage, speed, or assist level ensure that your bike’s motor speed controller has the right wiring and connectors. Some e-bikes will allow you to set a speed limit while using throttle assist. This usually can be achieved if you set programming for the motor speed controller. There are some sophisticated controllers which can provide CAN bus data that’s how you may use the display to see power level, speed, and estimated remaining mileage.

The Functioning Of An Electronic Bike Speed Controller

electric speed controller function

The speed controller is an electronic circuit that controls the speed of an e-bike motor and also serves as a dynamic brake. The E-bikes controller unit takes energy from the battery pack and drives it through the hub motor. The adaptive e-bikes require a conversion kit and the controller key component of the kit.

The bike’s speed controller monitors and conveys signals to the bike's motor hub in diverse voltages that turn up the direction of a rotor( metal disk) relative to the starter coil. A speed controller's proper functioning depends on engaging various mechanisms.

In a purpose-built e-bike, the Hall effect sensors specify the orientation of a rotor. If a speed controller does not have such type of sensors and speed controller on the adaptive bike, the electromotive force of the undriven coil calculate for having the rotor orientation.

Frequently Asked Questions

The AC motor controller controls the speed of the AC motor, it also can be referred to as a variable frequency drive, converter, adjustable speed drive, and more. An E-bike AC motor receives power that is converted through an AC motor controller into an adjustable frequency.

A controller manages the whole functioning of an E-bike. It is a component that makes a connection among all the electronic parts of a bike. It connects the battery, motor, display, throttle, paddle assist, and sensor that’s why it’s known as the heart of an e-bike.

A speed controller controls the speed of the bike by changing the frequency and amplitude of the motor. Using this system there is no possibility of losing heat, even the speed control provides numerous programs which involve the operation process of the machine.

Repairing a motor controller does cost and you can buy a new controller within 30 dollars. So, it’s better not to spend your money and time on repairing a new battery.


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The electric bike’s speed controller assists to ride in without engaging much physical effort and also ensures smooth and safe riding. Almost all e-bike speed controllers are preprogrammed to restrict their rider's speed limit when it reaches 20mph. This is how the riders can keep themselves safe from any injuries caused due to overspeeding. This innovative device can be removed and keep an option to have your freedom of riding. So, however, if you want to operate your bike, make sure you are not breaking the traffic rules.

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Hi, I'm Kevin Pommells, a lover of camping and the great outdoors as everyone says nowadays. I'm also a passionate soccer fan and the proud owner of, a website dedicated to helping campers and outdoor enthusiasts make the most of their adventures. With years of experience exploring the wilderness and a deep love for the sport of soccer, I'm always looking for new ways to combine my two passions and share my knowledge with others. Follow me for tips, tricks, and insights on all things camping and outdoor recreation.

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