The main thing that sets an electric bike apart from a standard bike is the motor. The motor helps power the e-bike forward even if the rider isn’t pedaling vigorously.
Basically, it’s what makes e-bike riding so fun (among other advantages)!
You can thank your e-bike motor for making your ride more comfortable, allowing you to ride longer distances and giving you the power you need to tackle all kinds of terrain, including hills.
But just how does an e-bike motor work? The answer depends on the type of motor.
Below, we’ll explain how three main types of e-bike motors work: the mid-drive motor, direct-drive hub motor, and geared hub motor. We’ll also highlight the pros and cons of each motor and reveal how to choose the right motor for your needs as a cyclist.
What e-bike motor options are there?
The electric bicycle motor powers the pedal assist system (PAS), which helps move the bike forward while you’re pedaling.
Some bikes also have throttle assist functionality: With this, the motor moves the bike forward even when you aren’t pedaling.
Different motors accomplish this in different ways. Here’s a quick breakdown of the mechanics of the most popular types of e-bike motors: mid-drive, direct-drive hub, and geared hub.
Mid-drive e-bike motor
A mid-drive electric bike motor is located in the center of the bike, between the front and rear wheels. More specifically, the motor is between the crank arms or “cranks,” the levers in the center of the bike frame that the bike’s pedals are attached to.
How mid-drive e-bike motors work
A mid-drive e-bike motor generates torque (a twisting or turning force that causes rotation) by a spinning shaft. This shaft is connected to a chainring, which is connected to the crank arms — which are connected to the pedals.
When the motor is activated, the spinning shaft creates torque. This engages the PAS and helps move the pedals.
Pros and cons of mid-drive e-bike motors
Mid-drive motors are popular among many e-bike manufacturers. Here are some advantages of mid-drive motors:
- Easy handling: Mid-drive motors are located centrally in the bike and low to the ground. This creates a low center of gravity that helps to balance the bike’s loads, adding stability and improving handling.
- Smooth ride: Mid-drive motors are efficient thanks to their central position. The motor’s central placement creates a direct link between the motor and the bike’s driving force, resulting in a smooth ride and less jerky acceleration.
- Longer range: Thanks to their efficiency, the best mid-drive electric bike motors have a long range. You’ll get more out of each battery charge. While it might not be noticeable for short rides, it can make a difference on long rides.
While mid-drive motors are efficient and create a smooth riding experience, they do have drawbacks. Here are some of their cons:
- Difficult to maintain: Mid-drive motors tend to be pricier to keep up. For example, the drivetrain (the components of the bike that power it forward) tends to wear down faster in this type of bike. Plus, if the chain connecting the cranks and pedals breaks, the PAS won’t work.
- Limited derailleur compatibility: A derailleur is a bicycle gearing system consisting of a chain, different-sized sprockets, and a mechanism that moves the chain between sprockets. Mid-drive motors aren’t compatible with a wide range of derailleurs.
- More expensive: Mid-drive motors aren’t just pricier to maintain. They also cost more to purchase upfront (compared to hub-drive motors).
Direct-drive hub e-bike motor
Direct-drive hub motors — also known as gearless motors — are located at the back of the electric bike. With this style of motor, the motor’s shaft doubles as the e-bike’s rear axle.
While the shaft in a mid-drive motor moves, a direct-drive hub motor shaft is fixed in place.
How direct-drive hub e-bike motors work
In a mid-drive motor, the shaft moves to create torque. However, in a direct-drive hub motor, this isn’t possible since the shaft is fixed in place. In a direct-drive hub motor, the motor (the “hub”) moves, rotating around the shaft.
The hub motor’s movement creates the torque that then propels the bike forward.
Pros and cons of direct-drive hub e-bike motors
Direct-drive hub motors have a few distinct advantages. Below are some of the features that make them popular:
- Simple: Because the hub is moving to create torque, there are less intricate moving interlinked parts. This allows for a simple, straightforward design. As a bonus, these motors are very quiet when they run.
- Durable: Since they don’t have a lot of moving parts, direct-drive hub motors are easy to upkeep. They’re durable and long-lasting and don’t have the high maintenance costs of a mid-drive motor.
- Affordable: In addition to not having high maintenance costs, direct-drive hub motors are also cheaper to purchase. This makes them a more economical choice.
While direct-drive hub motors are affordable and durable, they also have drawbacks. Here are some of their cons:
- Unwieldy handling: Hub motors tend to be bulkier and weigh more than mid-drive motors. This adds to the bike’s overall weight and can make for unwieldy handling. Plus, since the motor is at the back of the bike, the weight is distributed unevenly, further affecting handling.
- Inefficient: Since the motor doesn’t have internal gears but generates torque by rotating the hub, this type of motor can’t generate as much torque. As a result, it can’t turn the e-bike’s wheels as quickly, resulting in less speed and overall inefficiency.
- Slow acceleration: The motor’s low torque and lesser speed can visibly impact the riding experience. Bike riders may notice the bike doesn’t accelerate as quickly and can also feel a slight drag when pedaling.
Geared hub e-bike motor
Geared hub motors are more like direct-drive motors. However, instead of the hub moving to generate torque (like in a direct-drive hub motor), a shaft moves to generate torque (like in a direct-drive motor).
The moving shaft generates torque that moves the hub through a complex interconnected gear system. The entire geared hub system is concealed within the hub of the bike.
How geared hub e-bike motors work
In a gear hub motor, the moving shaft is connected to the wheel axle. (This is different from a mid-drive motor where the moving shaft is connected to a chainring, which connects to the crank arms and pedals).
In the gear hub motor, the electric motor inside of the gear hub spins, and the shaft inside of that motor connects to the gears that spin the hub. While the shaft inside of the gear hub spins at a high speed, the hub spins at a slower speed. This allows for greater torque but less speed.
Pros and cons of geared hub e-bike motors
Here are some of the perks of geared hub e-bike motors:
- Affordable: Geared hub motors are cheaper than mid-drive motors and generally easier to maintain, resulting in lower costs overall. This makes them an affordable option for first-time e-bike owners.
- Lightweight: Geared hub motors aren’t particularly bulky or heavy and are overall smaller and lighter than their gearless counterparts. This can make them easier to handle.
- No drag: Geared hub motors create good torque, which helps reduce the amount of drag the cyclist experiences (compared to direct-drive hub motors). Plus, they allow for faster acceleration than direct-drive hub motors.
While geared hub motors are affordable and create an easy riding experience, they aren’t perfect. Here are some of their cons:
- Inefficient weight distribution: Like their gearless counterpart — the direct-drive hub motor — geared hub motors are located at the back of the bike by the rear wheel. This results in uneven weight distribution, which can make for difficult handling.
- Poor traction control: The uneven weight distribution also results in poor traction control. This is because the bike has more weight placed over one wheel than the other. The wheel with less weight on it has poorer traction.
- Low maximum sustained power: A geared hub motor isn’t very efficient. As a result, it can’t sustain maximum power for extended periods of time. For people who want to ride long distances, this isn’t ideal.
Mid-drive vs. hub e-bike motors: Which is better?
Now it’s time for the great debate: mid-drive versus hub motors.
Mid-drive motors are generally considered mechanically superior, as they are the most efficient, offer a smoother ride, and promote easy handling.
However, that efficiency comes with a price.
Mid-drive motors are mechanically complex, which means they generally require more maintenance. Plus, they’re more expensive to buy.
Cyclists who want a bike for everyday purposes like commuting to work or getting some exercise may want to skip the hassle and expense associated with a mid-drive motor and opt for a hub motor instead.
A high-quality hub motor can be more affordable, simple, and durable. You won’t have to stress about upkeep as much as with a hub motor.
Finally, note that the type of motor is just one consideration when choosing an e-bike. You’ll also want to consider details like motor power (wattage) and range (how long the bike can go without needing to recharge).
For example, a 500W motor is plenty for a road bike. But an electric mountain bike (MTB) motor may need more power to go up steep inclines.
Beyond the motor, there are other aspects to consider too — like the bike frame type. Plus, once you get the bike, you’ll have to make sure it fits properly by adjusting details like the seat post and handlebar height.
Our point is this: Picking the right electric vehicle requires more than simply choosing the right motor! When you drive ebikes, you want to be comfortable, so doing research to pick the right bike is important.
Discover the best Velotric e-bike options for you
The Discover 1 has a 500W e-bike motor, while the Nomad 1 has an even more powerful 750W e-bike motor (and fat tires, making it better for off-roading). Both are Class 2 e-bikes with five-level pedal assist and throttle assist.
Each bike comes with a rechargeable battery and charger, and the battery charges completely in just six hours. The lithium-ion batteries are certified by Underwriters Laboratories (UL 2271) — a global standards safety organization — and considered Tesla-grade. You can easily check battery power with the easy-read LCD display.
Our e-bikes also come with safety features like headlights, front and rear fenders, and Shimano- hydraulic disc brakes. Plus, you can add extras like a rear rack for storage.
The Nomad 1 and Discover 1 can reach top speeds of 20 miles per hour. Each bike comes in two frame models, high-step and step-through (learn more about frame models). The high-step bike is ideal for riders from 5’6” to 6’9,” while the step-thru is ideal for riders from 5’1” to 6’4.”
With Velotric, you get high-quality craftsmanship at a cost-efficient price. Plus, you can ride with confidence knowing that Velotric’s bike frames have been rigorously tested — more than 150,000 times — with your safety in mind.