In 2015, this was a no-brainer, since all electric skateboards used belt drive motors. In 2016, hub motors began to be introduced and many of the newer boards are using hub motors today. For example, the first generation of our best all-around board, Enertion Raptor 2, used a dual belt drive motor and today it uses dual hub motors. Just to be clear, these are NOT two different motor types. Both drives are based on the brushless DC motor. The difference is in the way the motor is used.
Belt Drive
For a belt drive configuration, there are two gears, a smaller gear (pulley) attached to the motor and the larger gear attached to the wheel. The belt is attached to the two gears and when the motor spins, so does the wheel.
image from boostedboards.com
Hub Drive
For a hub drive (also known as direct drive), the motor is directly attached to the wheel but there are a number of variations. The motor itself could be embedded in the hub of the wheel so that the motor and the wheel spin together. The mellow drive is an example of this.
Jed Boards uses metal gears in direct contact with one another to spin its wheels (Jed Drive). The advantage of the Jed Drive is that it allows for more wheel options whereas for the direct hub drives, wheel options are limited to the manufacturer to engineer the parts which can interface with their in-wheel hub drives. Carvon skateboards also moved the motor out of the wheel by using an adapter to connect to the hub.
image from mellowboards.com
image from jedboards.com
Below is a brief comparison, but keep in mind that hub driven motors are a relatively new technology for electric skateboards. Over time, there will be improvements and some of the disadvantages may be eliminated as more technological advances are made. One disadvantage a year ago was limited wheel options and both Jed and Carvon provide a nice solution to address the wheel issue. A year from now, we may have to add more columns to address the different variations of hub drives. For now, we will keep it simple.
Belt Drive vs Hub Drive Table:
Belt Drive | Hub Drive | |
|---|---|---|
Technology Maturation: | 20 Years+ | 2 Years+ |
Foot Power (if battery dies): | The attached belt creates a lot of friction and make it difficult to move the board | Moves more or less like a regular skateboard |
Maintenance: | More moving parts (belt and pulleys) and they are usually not protected | Less moving parts and covered within the wheel's hub |
Weatherproof: | Since the belt and pulleys are usually exposed, likely to accumulate dust and moisture | Much less susceptible to dust and moisture due to the motor and the moving parts fully enclosed within the hub. |
Acceleration: | The gearing provides much better torque, hence faster acceleration. | This disadvantage may narrow over time |
Braking: | The gearing and pulley translates to less efficient braking, but this is a slight disadvantage | Greater control over the braking since the motor is directly connected to the hub |
Incline: | Gearing system provides better torque for climbing hills | Disadvantage here is small and may even be an advantage over time. |
Wheels: | For the most part, better options than direct hubs, but you are still limited to wheels that allow you to mount the pulley. | Jed Boards have find a way to eliminate this issue, but for other direct drives, this is still an issue |
Heat Dissipation: | The separation of the motor and the wheel results in much less heat dissipation, hence better protection from nearby components (i.e. battery) | Heat dissipation is a big design concern and can also impact the safety of the board |
Motor and Wheel Durability: | The gearing and lesser heat dissipation should provide a longer operational lifetime for the motor and the wheels | More studies need to be done as hubs evolve, but it seems that the heat dissipation and the vibrations inside the wheel would shorten both the motor and wheel's lifespan. |
Efficiency: | The efficiency is less due to the pulley and belt system. | Motor is near 100% efficiency because the gearing is 1 to 1, but over time slippage may occur. |
Noise: | The belt running along the gears results in more dBs. | The motor enclosed in the hub helps mitigate the noise, but it should be pointed out that the Jed Drive's two gear system make this a disadvantage. |
Weight: | Pulleys, belt, and usually bigger motor adds more weight. | Smaller motor and less parts give hub motors a clear advantage. |
Ride: | Ride may be softer (more suspension) since the hub within the wheel may give it a stiffer ride. | The Jed Drive and Carvon drive makes this a tossup |
As you can see, there are tradeoffs with both choices, but we would lean towards using hub drives for doing high quality builds, but belt drives for lower budget builds.