There are only two choices when it comes to installing hub motors: a front or rear hub motor. There are a few electric bikes that have hub motors mounted as mid drive motors. But this is not the focus of this article. You’ll find the same hub motors in both the front and rear of the kits if you do a search. This raises the question, “What’s the difference?” Hub motors: Weight matters
When deciding between front and rear hub motors, there are a few things to keep in mind. Let’s begin with the weight.
You should try to distribute the weight of your electric bike as evenly as possible from front to back. It is not a good idea to have all of your weight in one place. The majority of ebike batteries are located in the rear or middle of the bike. A 26 inch front wheel ebike kit can help spread the weight forward and improve the weight distribution.
Heavy rear hub motors and heavy batteries mounted further back, such as on a rack, can cause “popping wheelsies” when accelerating. This can happen especially if the motor is very powerful and/or the wheels have a smaller diameter.
Although it sounds fun, it can be quite annoying when the wheelie behavior occurs every time you move after a stop sign or red light. If it happens on an uphill, it can be dangerous. It is not a good idea to let someone ride your ebike, and then have them flip it upside down on their first attempt.
Hub motor placement can affect traction
Another important factor is traction. Although moving the hub motor forward to the front wheel solves weight distribution problems, it can also cause traction control problems. A front hub motor with less traction is more effective because there is much less weight on the front wheel than the rear.
A front hub motor will cause you to “peel out” when you accelerate with a higher voltage wheel. A 26″ wheel with a 36V hub motor can get good traction. However, a 20″ wheel with a front hub motor will almost certainly experience a spinning front wheel.
The rear wheel supports most of your body weight, so a rear hub motor will provide more traction than the front. A rear hub motor wheel would not spin freely on a dry road if it was powered by a motor with 48V or less. You can still get any wheel to spin if you are one of those guys pushing the limits on high voltage and high-power ebikes.
Flat tires and hub motors
Flat tires are another thing to consider. Flat tires are more likely than your front to be punctured by road debris.
Why? Your front tire can often lift objects that were originally flat on the road. Because they are flat, they don’t cause any damage to the front tire. They bounce off the front tire’s impact, but every once in a while you might be lucky enough to see them align perfectly to spear your rear tire when it is passed over again.
Flat tires can be more frustrating to repair in a hub wheel wheel than in a standard wheel. If you have a rear wheel hubmotor, you might find yourself needing to replace a flat tire. No matter if you choose a rear or front hub motor, my article about avoiding flat tires will help you to make it a non-issue.
Consider your hub motor installation
Front hub motors are also easier to install than rear motors. There is no need to transfer the freewheel over or adjust your derailleur in order to eliminate that annoying chain noise.
A front hub motor is easy to install. Simply swap the tire and then place the motor in the dropouts. Installation of front hub motors is simple, no matter what it means.
The advantages of rear hub motors are still there
Rear hub motors are still not available. Many people want their electric bike to look just like a regular bicycle, without any obvious signs of their “assistance”. Many small hub motors almost disappear behind the rear wheels’ gears, and are often covered with the disc. This makes the bike look more stealthy and hides the obvious front hub motor.
Because of their higher power, powerful hub motors can also be used for rear installations. This is because they are easier to handle by having stronger dropouts at the rear.
Front hub motors are simpler to install and have fewer flat tires. They also help distribute the weight more evenly. However, rear hub motors provide better traction and smoother acceleration.
Practically, smaller, weaker hub motors are used on the front to maximize the bike’s weight distribution and avoid tire spin issues. Larger, more powerful hub motors in the rear are used to benefit from the increased traction. It all comes down to what you like the best.
