Last Updated on May 17, 2023 by Matt
The electric bike motor is a core element that plays a crucial role in deciding the bike’s efficiency, performance, and overall riding experience.
It’s one of the biggest factors you’ll need to consider when buying an electric bike. In this guide, I will let you know everything you need to know about different e-bike motors, so you don’t feel lost when choosing between the available options and you make the best choice for your needs.
Electric bike motors
Electric bike motors have a power ranging between 250-750 Watts, but higher-end ones can go over 1000 Watts. The most important thing to consider when getting an electric motor is the purpose you’ll be using it for and how powerful of a motor you’ll need. You’ll also need to decide between a hub or mid-drive motor, brushed or brushless DC motor, and geared or gearless motor.
Do electric bikes have motors?
Yes, every electric bike is equipped with a motor to assist the rider in pedaling. It’s what distinguishes an electric bike from a traditional one. Some bikes even have motors that completely propel the bike forward without needing the rider to pedal.
Most electric bikes have one motor in the hub of either the rear or front wheel, but the electric bikes designed for rough terrains, e.g., cargo bikes, mountain bikes, etc, may have more than one motor.
Which motor is used in an electric bike?
Most electric bikes are fitted with brushless DC motors, aka BLDC motors. The BLDC motor is usually one of two types, a mid-drive motor or a hub motor. The choice of the motor for an e-bike usually depends on its intended purpose.
Electric bike motor specifications
| Specification | Metric |
|---|---|
| Peak power | Watts (W) |
| Real power | Watts (W) |
| Motor voltage | Volts (V) |
| Torque | Newton-meters (Nm) |
| Revolutions per minute | Number (RPM) |
Most of the time, you can judge the performance of an electric bike motor just based on the above parameters.
The real and peak powers are usually measured in Watts and tell you about the bike’s top speed, climb angle, weight limit, and acceleration ability.
With the motor voltage, measured in volts, you learn about how much electrical energy the motor can convert into mechanical power to drive the bike.
Torque measures how much force can be applied. The torque is measured in Newton meters (Nm).
Lastly, the revolutions per minute parameter determines how quickly the motor can increase in speed and then maintain it. It’s measured in rotations per minute (RPM).
How does an electric bike motor work?
An electric bike motor is usually activated when the rider starts pedaling or activates the throttle. When the controller gets this information, it signals the motor to generate power using energy from the battery to propel the bike.
The amount of power the motor generates depends on how much of the throttle you want to use, your chosen pedal assist level, and the force you apply on the pedals, which is detected by a torque sensor.
Most electric bikes are equipped with brushless DC motors. A BLDC motor has a stationary part called a stator, and a rotating part called the rotor. The stator is made of wounded coils and is surrounded by the rotor, which is attached to a permanent magnet with two standard magnetic poles.
A magnetic field is generated when an electric current passes through the stator’s coils. This causes the permanent magnet and the electromagnet to work together to rotate the rotor. When one stator coil energizes, the opposite poles of the rotor and stator attract each other and rotate the rotor. When one coil de-energizes, its neighbor coil energizes to continue the rotation.
Electric bike motor power
The electric motor power decides the overall performance of your electric bike. A higher-powered motor means your bike can handle more load, have a higher top speed, and offer increased torque to climb hills easily.
On the downside, a higher-powered motor also means more battery consumption and heat generation. Not only are these motors heavy themselves, but they also require heavy, high-capacity batteries to power them.
This is why high-powered bikes are more expensive.
Power levels in electric bike motors
Typically, electric bike motor powers range between 250-750 watts, but faster or higher-end bikes can have motors with a rating of over 10000 Watts, and often times much more than that. The most common power levels in electric bikes are 250, 500, 750, and 1000 watts.
A 250-watt motor works well for a regular commuting bike. You’ll get a top speed between 15-20 mph / 25-32 kmh, with enough power to climb average hills. Though the acceleration won’t be as fast as other higher-powered bikes, it’s still decent enough for a basic, budget-friendly electric bike.
A 500-watt motor will give you a top speed between 20-25 mph / 32-40 kmh, fast acceleration, and has decent hill climbing capability. The bike will be more expensive than a 250-watt electric bike but still reasonably priced compared to other e-bike models.
750-watt motors are where electric bikes start getting expensive. These e-bikes have a top speed between 25-30 mph / 40-48 kmh, and are great for climbing steep hills and tough terrains.
An electric bike with a 1000-watt motor is typically quite expensive but can give you a top speed of over 30 mph / 48 kmh. These bikes make climbing steep hills feel like a breeze and are known for their rapid acceleration.
Real vs peak power
The motor powers specified by electric bike manufacturers are sometimes misleading.
An electric bike motor has two kinds of powers: a real power and a peak one.
The peak power is the maximum power a motor can generate in ideal riding conditions. Ideal conditions would be riding on an even, smooth road, without stopping, and in moderate weather.
However, the riding conditions are rarely ideal, and even if the bike manages to reach peak power, it’ll be short-lived because the motor will heat up.
Real motor power, on the other hand, is the power the motor can generate and maintain in practical conditions. This means the bike will sustain this power even on uneven roads, during traffic, and while climbing up steep hills.
The thing is that the majority of e-bike brands only mention the peak power of their bike models to make them look better. Often, they’ll mislead customers by stating a single power rating without specifying if it’s the peak or real value.
So, what I like to do in such a scenario is to just assume they’re talking about the peak power. The approach may fail sometimes, but it’s worked pretty good for me so far.
The real power of an ebike motor is usually around 60% of the peak power. This can vary, but the value will always be between 30%-90% of the peak power.
If manual calculation isn’t really your cup of tea, you can use our real and peak motor power converter to help you out.
Power in electric bikes vs. other appliances
Comparing the power of an electric bike motor to the power of common household appliances will give you a frame of reference to understand the energy consumption of an e-bike motor.
| Household Appliance | Power (Watts) |
| Blender | 300 – 1200 W |
| Microwave | 800 – 2000 W |
| Toaster | 800 – 1600 W |
| Hair Dryer | 1000 – 2000 W |
| Vacuum Cleaner | 400 – 1500 W |
| Refrigerator | 500 – 1500 W |
| Washing Machine | 500 – 1200 W |
| Laptop Computer | 20 – 100 W |
| Desktop Computer | 200 – 500 W |
| Plasma TV | 250 – 300 W |
| Video Game Console | 40 – 150 W |
You can observe from the following table most of the bigger appliances have powers similar to higher-end electric bikes.
How powerful of an ebike motor do I need?
This really depends on what you plan on using your electric bike for. If you’re looking for a casual electric bike to run errands and mainly ride on flat roads, a 250-300 Watt motor will do the trick.
For more challenging terrains and circumstances such as hills and offroad trails, you’ll need a motor power between 500-750 watts for a smooth ride.
If you need something faster for longer, dedicated, off-road riding or want a bike that can handle more load and offer more assistance, you could go for a bike with a higher-powered motor. Keep in mind that this will increase the overall cost and weight of your bike.
Electric bike motor torque
Torque is the turning force an electric bike motor produces to turn the wheels of an electric bike. The value of the motor’s torque plays a big role in the bike’s performance, especially if you plan on riding the bike on hills and mountains.
The higher the torque of the motor, the easier uphill climbs will be. On average electric bikes usually have a torque between 30 and 85 Nm, but depending on the electric bike model, it can go higher than 100 Nm as well.
Most electric bike manufacturers don’t mention the torque of the bike. If you’re considering an e-bike for off-road riding and tough terrain, I highly recommend contacting the manufacturer for its torque value.
Hub vs mid-drive motors
Most electric bikes are fitted with a mid-drive or hub motor. It’s important to understand the key differences between them to make an educated buying decision.
A hub motor is the more common and often cheaper motor of the two, usually fitted in the hub of the e-bike’s rear wheel. Some bikes also have a second motor in the hub of the front wheel. This type of motor directly powers and rotates the wheels without any contribution from the drivetrain.
A mid-drive motor, on the other hand, is fitted between the pedals of an electric bike and drives the front chainring of the bike. This means it works in combination with the drivetrain and can’t work without it.
Both motor types have their pros and cons. A mid-drive motor is easy to maintain and provides better riding quality. It offers better weight distribution than a single hub motor in the rear wheel as well.
Since the motor is attached to the drivetrain, it can work together with the gears to give you more range and power to climb steep hills. The wheels of a bike with a mid-drive motor are also easier to change in case of a flat tire.
On the downside, bikes with mid-drive motors are more expensive. Also, a mid-drive motor is dependent on the rider’s pedaling. So, there is no throttle feature like the one you would get with a hub motor.
The following video goes into more detail on the advantages and disadvantages of both types of motors.
Which is better hub motor or mid-drive motor?
Hub motors are great if you plan on riding your bike mostly on flat ground and want a simple and reliable motor. They’re also quieter than mid-drive motors.
However, if you live in a hilly area or are getting an e-bike mostly for riding off-road and on mountains, a mid-drive motor will give you more power and torque.
What is the difference between hub-driven and chain-driven motors?
Chain-driven motors power the e-bike’s chain to move it forward. A mid-drive motor is an example of a chain-driven motor.
Contrastingly, hub-driven motors directly power the wheels of an e-bike and do not work with the drive train in any way.
Belt-driven vs. chain-driven motors
Like a chain-driven motor, a belt-driven motor is also located near the bike’s pedals. The only difference is that instead of having a chain, the motor has a belt to turn the wheels of the bike.
A belt-driven motor requires less maintenance and offers a smoother and quiet ride. However, for off-road riding, steep hills, and mountains, a chain-driven motor works much better.
Geared vs gearless motors
Hub motors can be divided into two types based on the gears they use: geared and gearless.
Gearless hub motors
A gearless hub motor, aka a direct-drive motor, uses an electromagnet in the form of coils to directly turn an e-bike’s wheels by producing torque. These motors are more powerful than geared hub motors, making them perfect for riding in high-speed and climbing uphill.
On the downside, they are heavier than geared hub motors and less efficient.
Geared hub motors
A geared hub motor has gears inside itself that spin. They transfer turning power to the hub and wheels to drive the bike forward. The constant friction in these motors leads to more wear and tear, decreasing the motor’s lifespan.
These motors are less powerful than gearless motors but are more energy efficient.
Brushed vs brushless DC motors
A brushed DC motor is made up of a rotor and commutator with brushes that rotate the rotor. When an electric current is passed through the motor, the rotor starts to spin. The brushes keep switching the polarity of the electrical current to keep the rotor spinning.
These motors are simpler and less expensive than brushless DC motors, but are also less efficient and require more maintenance. Also, the friction caused by the brushes can decrease the motor’s lifespan.
The following video does a good job of explaining the basics of how a brushed DC motor works.
Brushless DC motors do not have brushes or a commutator. Instead, they use a series of magnets to create a magnetic field that energizes and de-energizes the electromagnetic coils to keep the rotor spinning.
These are more complex and expensive than brushed DC motors but more efficient and require less maintenance.
How do I choose an electric bike motor?
Here are some tips to help you decide on the right electric bike motor for you:
- Determine how you intend to use the electric bike. Do you need something to run errands and for regular commutes, or do you need a bike that can handle rough terrains and heavy loads?
- Once you’ve decided on what you’re going to use your electric bike for, consider the power and torque of the motor you’ll need. For climbing up steep hills and conquering rough terrains, you’ll require a high-powered motor with increased torque.
- Now, decide on the type of motor. A hub motor is more efficient and will drive your bike even without pedaling. A mid-drive motor is more expensive but efficient if you need more power, speed, and torque.
- Remember that a mid-drive motor isn’t your only option for a high-powered motor. Getting a hub motor with higher wattage can also help you with steep hills and off-road riding.
- Research reliable brands and check reviews to see which motors served reviewers best.
What is the most powerful electric bike motor?
The 12000w ENDURO eBIKE has the most powerful electric bike motor in the world right now with a power of 12000 watts. Sold at a whopping $4,399.00, the bike has an equally strong 72V 47 Ah battery to power the motor.
Which type of electric bike motor is best?
In general, I recommend going for a brushless DC hub motor because they are more efficient and require less maintenance. I recommend a hub motor with a higher wattage if you plan to ride your electric bike off-road or up steep hills mostly.
If you just need a motor sufficient enough to help you smoothly run errands and for commuting, no need to spend a ton of money on a higher-wattage motor. A 250-500 Watt motor will do just fine.
How to maintain the motor on my electric bike?
Brushless DC and hub motors require little to no maintenance, so just getting the motor checked once a year by a mechanic for a regular tune-up is enough.
Here are some basic maintenance tips to take care of the motor between the yearly check:
- Avoid using high-pressure water near the motor when cleaning your bike.
- Don’t ride your bike at maximum speed for too long because it will cause the motor to overheat.
- Refrain from overloading your bike with baggage and heavy accessories. The weight will put a load on the motor and cause it to overwork and overheat.
- Similarly, don’t try riding your bike up hills steeper than it is designed for. The motor will have to overcompensate and can end up failing or overheating.
- If your bike is among the rare few that have a mid-drive motor, lubricate your bike’s chain once every few months.
