One of the most common questions we encounter is about the motor of an electric bike. The motor performs an essential role in assistive pedaling, which makes an eBike faster and easier to ride. Brands are laying out specs that get more technical as the market evolves, which creates confusion. We will cover the basics so you can make an informed choice for your next eBike motor.

What a Motor Does

The motor of an eBike produces power allowing the rider to exert less physical effort in propelling the eBike forward. It supports your pedaling rather than replacing it, making every ride smoother and farther. It helps when starting from a stop, climbing uphill, or maximizing the cargo capacity. The assistance is possible through two ways — throttle (available on class 2 eBikes) and pedal assist (available on all eBikes). Let’s discuss them one by one.

Throttle

A throttle engages the motor and it propels the eBike forward even without pedaling. Only class 2 eBikes are equipped with this and in combination with pedal assist. When the rider twists/presses the throttle, it helps increase the motor output. A throttle comes handy during stop-and-go, climbing uphill, supporting cargo weight, and recovery of the rider, among others.

Pedal Assist

The pedal assist in an eBike allows it to still feel like riding a regular bike — but better. EBikes are faster but gentler on the knees as it senses active pedaling and sends signals to the controller. The controller takes it into account and utilizes electricity from the battery to deliver a motor output. One key component in the whole process is the sensor and it has two types worth learning about — the cadence and torque sensors.

Cadence

A cadence sensor is a straightforward sensor type because once you start pedaling, the motor receives a signal from the controller and returns the level of assist the rider indicated. There is a level of assist preset for eBikes and switching pedal assist is as easy as shifting with a +/- button. EBikes with this sensor are recommended for commuting or daily urban rides because of the consistency and predictability it offers.

Torque Sensor

A torque sensor provides a smoother riding experience. This sensor makes the ride experience feel very much like a bike ride. Unlike cadence, this sensor can detect the force applied on the pedals and can provide more accurate pedal assist — higher pedaling force will return a higher level of assist. The sensor can reflect the pedal input into the change in power output. Don’t worry, a +/- is still within your reach so you are still in control of your speed. 

Good News!

There are electric bikes that lets the rider switch between sensors since they carry both systems. You may want to check out the brand Velotric because they have trademarked the SensorSwap™️ technology.

Comparison Table (Cadence vs. Torque)

Motor Placement

The two placements of eBike motors are at the hub of the wheel and at the bottom bracket. Generally, hub-drive and mid-drive motors differ in location in an e-bike. They mostly have similar functions, but they are different in terms of build and performance. 

Hub Drive

A hub-drive motor is designed directly on the wheel and it drives that same wheel for propulsion. There are 2 wheels in an eBike so a hub motor can be on either one of them. Users report that there is either push or pull feeling depending on the location of the motor. If you are a beginner, you will possibly have an adjustment period with a hub motor because the added weight either interferes with balance (rear hub) or steering (front hub).

- Front Hub Drive Motor: Front Wheel

- Rear Hub Drive Motor: Rear Wheel

Mid Drive

A mid-drive motor is designed at the bottom bracket and in between pedals of an eBike. This motor offers a smoother feel when pedaling, a more balanced design, and low center of gravity. It is also usually paired with torque sensors since they are conveniently placed with the crank. Together with the torque sensor, the eBike can have smooth power transitions. Additionally, there are class 2 eBikes with mid-drive motors, so the throttle can further help during off-road rides. Once all these advanced components come together, the price of an eBike also increases, which is why they are usually all present on pricey, high-end eBike.

Torque Explained

The torque of an e-bike is a significant parameter in a motor’s performance because it works with power so your eBike can overcome steep terrain. Mechanically, torque is the twisting force causing the object to rotate from a certain distance and measured in Newton-metre (Nm) or pound-ft (lb-ft).

How does it work?

→ The rider puts pressure when pedaling

→ The sensor will measure the amount of force exerted on the pedal

→ The controller analyzes this and sends signal to the motor

→ The motor will produce torque either on crank (mid-drive) or on wheel (hub drive)

How Much Torque Do I Need for My Cycling Style

Low-Range Torque:  Recommended for urban riding or daily commutes

Mid-Range Torque:  Can be confidently used for m oderately challenging terrain or city eBikes with slightly heavier load

High-Range Torque: Often found on off-road and cargo eBikes

Remember, it is not about having high amounts of torque, but what can satisfy your needs and your lifestyle.

Ride Feel

The ride may feel different depending on the motor. The hub drive is independent from the drivetrain so some feel a sudden push from where the hub motor is located. Meanwhile, riders feel more connectedness and responsiveness with a mid drive motor because they are designed directly to the drivetrain.

The type of sensor may also contribute to the ride feel of an eBike. Cadence sensors have noticeable steps, which have been described as ‘jerky’ by some riders. This jerk and consistent assistance is ideal for delivery and urban riders because it is more predictable and easier. Torque sensors feel more proportional to your effort, giving a natural and smooth assist. This is preferred by riders who enjoy off-road rides and have fitness goals.

Conclusion

Complicated specs is currently a trend in the market because it aims to build trust among consumers, especially for complex parts like motors. However, numbers can get really confusing, so it is important to consider how the eBike feels on the road and how it responds to you. Understanding how a motor works, gives a better view of how it fits with our style. The next time you look for an eBike, you can make better choices. There is really no best eBike motor, only what’s truly best for you.