Almost all electric skateboards are powered by either an in-wheel hub motor, or a belt driven externally-mounted motor. We're going to explain the main advantages and disadvantages of both of these designs, so you can make the right buying decision. We will break them apart below starting with hub drive motors.
A hub drive motor transfers power directly to the wheel, because the hub motor IS part of the wheel. Confused by how that’s possible? It’s actually quite simple. Do you remember when you were a child and you would take your toys apart, much to the anger of your parents that spent money to buy them? Well if you did I’m sure you came across the common DC motor similar to the one below.
This type of motor powers millions of children’s toys, from cheap rc cars to the autonomous drones. These motors also power every electric skateboard currently on the market today. Now if your take that electric motor, enlarge it, wrap some Urethane rubber around it, and attach it to an axle, you'll have created the same hub motor that powers an electric skateboard. In a nutshell, this is how a hub motor electric skateboard works.
Now how does a belt drive electric skateboard work? This one is a bit simpler, and the motor is attached to the board separately from the wheels, usually to the trucks via a bracket. There is a gear on the motor shaft and a gear on the running wheel, and a rubber belt connecting the two together. Boosted Boards is the largest manufacturer of electric skateboards, and their boards primarily feature a belt drive. The motor rotates the wheels via a belt, similar to the same way you pedal on a bicycle and the front sprocket drives the rear sprocket via a chain.
So which is better? Now that you know exactly how a hub drive and belt drive electric skateboard works, which one is better? Well, they both have their advantages and disadvantages. Read below.
1. Higher top speed:Since there is no gear drive to multiply torque at the expense of speed, a hub driven electric skateboard is usually engineered to deliver a higher top speed versus an equally constructed belt-driven board.
2. Quiet operation: The hub motor is quieter. Not only is it wrapped in Urethane rubber, but there is no gear drive to make any additional noise. Due to this, you can cruise around town or on school campus incognito, and few can tell you're not riding just a regular skateboard.
3. Less maintenance and wearable parts: No gear drive, belts or chains mean nothing to lubricate or replace, thus reducing maintenance and cost. It also makes the motor water resistant as there are fewer places for water to get into.
4. Ability to freewheel: Hub motors provide the least amount of friction when not being powered. So when the battery runs out, a hub motor powered electric skateboard is fairly easy to push on, especially compared to a belt-driven board.
5. Lighter: Hub motors combine the wheel and motor into one unit, and therefore are lighter than a comparable belt driven electric skateboard..
1. No torque multiplication: Hub motor electric skateboards will usually have less torque than a comparable belt-driven electric skateboard. This is because when using a belt drive, you can change the size of the drive gears to multiply torque. On a bicycle this is similar to how the front sprocket connected to your pedals is larger that the rear sprocket, so as to be able to multiple torque at the expense of speed. So usually, a belt driven electric skateboard will have more torque for going up hills and steep terrain. A hub driven board can only provide a direct 1:1 drive ratio, because the motor is connected directly to the wheel and there is no gear drive in between to multiple torque.
2. Harder to change wheels: Since the motor is contained within the wheel, you can’t swap wheels as easy as you can on a belt driven electric skateboard. Hub driven boards usually have less options when it comes to swapping out wheels.
3. Less heat dissipation: Hub motors are wrapped in a Urethane rubber sleeve, and therefore will store heat more than an externally-mounted motor on a belt-driven board that is exposed to air circulation.
1. Higher torque: A belt drive allows for an input gear on the motor, and an output gear on the wheel. Changing the size of these gears will change the torque multiplication available from the motor, just like how a car’s transmission also changes available torque to the wheels depending on the gear the transmission is in. With that said, hub motors are not at as much of a disadvantage as you might think they are. Newer boards on the market have optimized their hub motors to be very competitive and can provide similar levels of torque without having to use gears and belts, due to the internal designs of the motor and changes to the electronic speed controller.
2. More wheel options: Belt driven boards will always have more wheel options compared to hub driven wheels. Since the motor is separate from the wheel, it can stay with the board and you have a larger range of compatible wheel types. Hub motors requite you to either swap out the entire motor/wheel, or the Urethane sleeve over the hub motor.
3. Better heat dissipation: A belt driven board has the motor attached to the trucks, and is open to circulating air when you’re riding. This provides better heat dissipation when compared to a hub motor that is insulated by a Urethane rubber sleeve.
1. Loud by design: Due to the nature of their design, belt driven boards are almost always louder. The belt itself will make some noise, and also the exposed motor. Ina hub driven board, the motor is wrapped in thick Urethane rubber since it is enclosed in the wheel. Not only does the rubber provide grip with the road, but it also make an excellent sound insulator. This makes most electric board whisper quiet, at least compared to a belt driven board.
2. Requires More Maintenance and Replacement of Parts: A belt driven board will need it’s belt replaced about every 300-600 miles depending on the board manufacturer. The exposed belt is also susceptible to dirt, sand, and the occasional rogue pebble that might cause it to snap. Replacing them is not too bad, but something to know about. A snapped belt will leaving you walking home however.
3. Very hard to ride without battery power: Belt driven are almost impossible to push on once the battery dies. This is because the gear drive provides an advantageous lever when the motor is running, but magnifies the friction in the motor when it’s not running. So when the battery runs out, there is a substantial amount of motor friction that makes pushing home a hard task. You’ll most likely have to carry.
If you want the absolute maximum amount of power out of your electric board, gear-driven boards can produce more power due to their torque multiplication factor. However, hub motors are quickly catching up to be able to match gear driven boards, although they are not quite there yet.
If you want a board that is quieter, lets you push on when the motor isn’t running, and requires less maintenance, a hub powered board is a better bet.Hub powered boards also produce substantially less noise due to the lack of gears and belts, and also due to the fact that the motor is wrapped in noise-insulating rubber. They also look sleeker and stealthier as the motor is not attached to the outside of the board and is therefore not visible. Hub powered boards also let you push easily when the motor is not powered, so it feels much more like a regular board when you’re just coasting. Lastly, hub motors require almost no maintenance as the motor is sealed inside the wheel and there are no belts to replace. On the other hand, hub powered boards provide a bit less power than their belt driven counterpart, and don’t allow many options if you want to swap out wheels.
Owner and rider at Electric Board Co.