The motor is one of the most important parts of an electric bike because it plays a big role in its performance.
Estimated reading time: 7 minutes
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How e-bike motors work
To assist, whether it’s by pedal or throttle, an electric bike needs a good motor. It’s an integral part of any e-bike, and it can be mounted to the front, middle, or back.
Related: What are the 3 e-bike classes?
The electricity from the battery is converted into mechanical energy. This is what makes your electric bike function.
Most e-bikes use brushless direct current (DC) motors (BLDC). Instead of the brush that old motors used to have, e-bikes have a rotor with permanent magnets and coils inside.
When the coils are powered by the battery, they become electromagnets. They attract and repel the permanent magnets when they’re energized. The repeated motion causes the rotor to rotate.
Being brushless makes the motor more efficient, boosts its performance, and functions quietly. It also leads to fewer mechanical issues.
Types of electric bike motors
There are several types of electric bike motors, and they’re placed in different locations. Unlike other aspects of the bike, the motor isn’t something you can easily swap out. That’s why understanding your options will help you choose the best e-bike.
The different types of e-bike motors are direct-drive hub, geared hub, mid-drive, friction, and dual motor. Each type of motor has pros and cons, and the best one for you depends on what you need in an e-bike.
A direct-drive hub motor is simple and affordable. It’s found at the hub of the rear wheel and works by propelling your forward. It also allows you to generate electrical energy through regenerative braking. If you cycle in the city or areas where there aren’t many hills, an e-bike with a direct-drive hub motor will suit your needs.
Geared hub motors are excellent because they’re affordable, offer great low-end torque, and are durable. It features an electric motor that spins much faster than a direct-drive motor. By turning faster, the e-bike can perform well while riding at low speeds.
Mid-drive motors are built into the bottom and center of an e-bike. Generally, e-bikes with mid-drive motors are more expensive because they offer exceptional performance, better weight distribution, stability, and has great low-end torque. They also thrive on different terrain and hills, as they have more power.
Friction motors are the easiest to mount and work by spinning a roller that’s pressed against the tire. They’re not ideal because they cause your tires to wear down faster. They may also not work well when it rains. Friction motors aren’t as common, and it’s better to go with a mid-drive or hub motor.
Dual motor e-bikes are fun to ride but less common. There’s one motor in the front and one in the back. They offer more power and allow you to take on hills and rough terrain much easier. Instead of feeling the push from one wheel, you’ll get double the help.
Along with the different types of motors, another important factor is the diameter of the motor. A motor with a larger diameter will have more torque regardless of the type.
How much power is necessary?
Aside from the type of motor, there are different power ratings. Generally, you’ll find that most e-bikes motors range from 250W to 750W. 750W is the limit for e-bikes in the United States.
When companies list the power output, it can be confusing. They don’t tell you the duration, which is a key fact. How long are you getting the peak or rated power?
Since there isn’t a standard for this, it can be for a few seconds or maybe a minute. The exact power output is different based on the electricity the controller sends through to the motor.
Broken down, watts are a combination of volts and amps. The voltage and amperage that flows to the motor will give you a better idea of how powerful the e-bike will feel.
However, the following are the different power ratings and what they’re best for:
- 250W: It’s best for city commutes without too many steep hills. If you’re a heavier rider, it may be difficult to go uphill.
- 350W to 500W: It offers more power and faster acceleration. Riders of all weights will be able to go up decent hills.
- 750W: Everything is faster and more powerful. Regardless of the payload, you can go up hills.
Torque is another important factor. It’s the rotational power of the motor. More torque equals stronger support when you pedal.
The best e-bike motors
The following are the best electric bike motors.
Best overall: Fazua Ride 50 Evation
Out of all of the electric bike motors, Fazua Ride 50 Evation is the best. It’s a 250W motor that only weighs 10.1 pounds, which is great. The Ride 50 Evation produces 55Nm of torque, which isn’t extremely high, but it gives you a good amount of assistance.
One of the best features is that you can remove the motor from the frame and ride it like a traditional bike. When you’re using assistance, it gives you a natural feel. It offers three levels, breeze, river, and rocket. It ranges from subtle support to impressive power.
Best for electric mountain bikes: Bosch Performance Line CX
If you need a compact, lightweight, and powerful motor to climb hills and conquer mountains, the Bosch Performance Line CX is the ideal choice. It only weighs 6.3 pounds, offers torque up to 85 Nm, and supports you up to 20 mph.
The sophisticated motor features sensors that ensure you have the smoothest ride. It gives you control over the trails and exhilarating performance.
Best for carrying heavy loads: Shimano EP8
Shimano EP8 is the ultimate motor for carrying heavy loads. It offers up to 85Nm of torque while only weighing 5.73 pounds. The motor gives your e-bike quiet, smooth, and direct power, which runs seamlessly.
The EP8 is also customizable, as you can use the E-TUBE PROJECT App to save your preferences. You can select between 10 levels of assist character, 5 levels of assist start, or select and set the maximum amount of torque across 3 modes.
Best for everyday riding: Yamaha PWSeries SE
If you’re an avid cycler or love to ride around the city, the Yamaha PWSeries SE is an excellent choice. It’s a 250w motor that produces up to 70Nm of torque. Weighing 7.7 pounds, it’s also lightweight.
It gives you enough power and torque to carry around your essentials without feeling resistance. Overall, it performs well, and you’ll have a smooth ride.
If your budget allows, get an e-bike with a mid-drive motor because it offers the best performance and durability. For something lower-priced, you can choose between a geared or direct-drive hub motor. If you’re a city commuter, go with the direct-drive motor, and for off-roaders, go with the geared hub motor.
Featured image courtesy of Canva.
About the author: David Em is the founder of Hello E-Bikes, the destination for electric bike reviews, comparisons, gear, and tips.