How Does The Motor Work On An E-Bike?
How Does The Motor Work On An E-Bike?
The motor is an important part of your e-bike’s electrical system — but it doesn’t work alone!
When you engage your e-bike’s throttle — or pedal with your pedal assist system activated — those components first send a signal to your e-bike’s controller.
Wait — what’s a controller?
Think of the controller like your e-bike’s brain: it receives instructions from the rider via the display or throttle, figures out what needs to be done, and sends commands to the battery and motor to carry out those instructions.
When the controller signals the battery, the battery sends an appropriate amount of power to the motor.
That amount is determined by the amount the rider engages the throttle, the speed at which they’re pedaling, and/or the level of pedal assistance they’ve selected.
Additionally, for e-bikes with a torque sensor, the amount of force with which the rider pedals also helps regulate the amount of power sent to the motor!
Hub Motors vs. Mid-Drive Motors For Electric Bikes
There are 3 main types of motors available for electric bikes. Two of them fall into the category of “hub motors” while the other — “mid-drive” — stands alone. Let’s take a look at each type.
Geared Hub Motors
Based on the name, you might think that geared hub motors leverage the mechanical gears on your bike for power — but that’s actually not the case!
The hub is a cylindrical case located on an e-bike’s wheel (usually the rear wheel), and the “geared” part refers to a set of gears within the hub. These gears regulate the speed at which the motor turns, which ensures that the motor delivers the correct amount of torque needed to power your e-bike. That amount of power can be anything from just a little boost up to your e-bike’s maximum assisted speed.
Geared hub motors are usually found on Class 1 and Class 2 e-bikes, which cap out at 20mph with motor assistance. That’s because these motors are well suited to provide lots of torque (force), but aren’t as impressive at the Class 3 e-bike’s faster speeds of up to 28mph.
Geared hub motors are an excellent choice for:
- Riders concerned with e-bike weight (these motors are very light)
- Riders who like to switch between pedal assist and “analog” riding (geared hub e-bikes feature freewheels that make pedaling easier)
- Powerful high-torque riding, such as going up steep hills and/or carrying heavy loads
Direct-Drive Hub Motors
Direct-drive hub motors do not feature any gears within the hub. Instead, the hub itself is the motor that turns the wheel using electromagnetic force.
One half of the hub contains magnets; the other contains wires that transmit power from the battery. The electric current coming through the wires activates movement thanks to the magnets, causing the hub to turn.
They’re a great choice for…
- Riders bothered by noisy e-bikes (direct drive motors are virtually silent)
- Riders who use pedal assist and/or throttle regularly (there’s no freewheel, which makes pedaling a bit more difficult when the motor isn’t engaged)
- High-speed rides, especially Class 3 e-bikes that provide motor assistance up to 28mph
Be aware that direct-drive hub motors are heavier than geared hub motors, which adds some weight to your bike. They’re also less energy-efficient overall.
Mid-drive motors are the only e-bike motor style that doesn’t feature a hub.
Instead, the motor is integrated into the pedals and crankset. It turns the chain, rather than the wheel.
Like a geared-hub motor, the mid-drive motor regulates the speed at which the motor turns. The difference is that a mid-drive motor uses the e-bike’s mechanical gears to do so, whereas a geared hub motor uses a unique set of gears integrated into the hub itself, separate from the e-bike’s mechanical gears.
It’s said that out of all motor types, e-bikes with mid-drive motors offer the best balance. That’s due to the fact that a motor is among the heavier components of an e-bike, which means that placing it on the front or rear of the bike can shift the bike’s center of gravity forward or back.
Instead, the mid-drive motor’s low central location between the pedals of a bike offers better balance and a feel more akin to riding a traditional bike.
Mid-drive motors are ideal for…
- Riders who want the most traditional bike feel while riding
- Riders who don’t mind higher cost (e-bikes with mid-drive motors tend to be the most expensive to manufacture, resulting in a higher price)
- Ease of changing tires or wheels (since the motor isn’t integrated into either wheel, removing wheels and tires on a mid-drive e-bike is easier vs. hub motors)
Our mid-drive models stand out from the pack in a few key ways:
- They feature both pedal-assist systems and throttles — throttles aren’t often seen on e-bikes with mid-drive motors
- They are truly high-torque motors — while other e-bikes claim high levels of torque at 90Nm (Newton-meters), ours give a whopping 130Nm of torque!