Let’s Talk About Drive Trains – Belts, Hubs, Gears, Oh My!

5th Sep 18 -Some edit done. Special thanks to Q from Predator Board for some valuable input.

Are you team belt or team hubs?

Many of us have very strong opinions on the best drive train for electric skateboards. This article’s primary purpose is to help those who are new to the eskate world pick sides.

Foreword

For the longest time, belt driven setups have been the prevalent option for electric skateboards. They’re efficient, easy to set up, and easy to maintain. From DIY to Boosted Boards, belt based drive trains are the standard choice.

Then the hub motors rolled around. They were uncomplicated, cheap, and readily available. Perfect for cheap yet effective boards.

By the end of 2017, however, something was gearing up to upset the power balance of the drive train universe.

Made famous by Jed Boards for its mind-blowing free roll ability and ear-drum blowing high-pitch noise, the gear drive started to garner a lot of attention. Enough attention to make many of us wonder if the future of electric skateboard does not belong to the hubs, but to the geared drive?

And what about direct drives? How do those affect the drive train space?

Belt Drives

The belt drive is the most traditional drivetrain. It connects a wheel to an outrunner motor with a system of belts and gear pulleys. As a tried and true drive train, it’s been the drive train of choice for eskate builders and is a staple of electric skateboard world. Boosted, Evolve, Metroboards are all based upon the belt drive.

Heck, the majority of DIY builders still go for belt drives!

While belt drive lovers typically swear by the belt drive train, many new eskaters are turned away from belt drives due to noise concerns, limited free-rolling ability, and the need for regular maintenance.

The belt drive system limits free rolling as there is a significant amount of resistance added due to the pulleys, which makes it harder to kick-push. Maintenance surrounding the belt drive such as belt changes due to wear or tear, belt-tensioning, and belt alignment might also scare away people who aren’t necessarily mechanically inclined.

That being said, there are still many good reasons for people to be loyal to belt drives.

Generally speaking, the belt drives deliver better torque than equally priced hub systems. They also allow the use of full longboard wheels as opposed to thin PU sleeved hub motors. This also allows for a wider selection of wheels to swap to and from. Plus, some people like to get creative with their setups and belt drives allow for more creativity in that department.

Hub Drives

From the ‘board of the year’ Raptor 2 to the relatively tame Inboard M1 to the budget champion MeepoBoards, hub motors can be found everywhere.

Hub motors came into the limelight when Jason Potter announced to the world that the Enertion Raptor 2 will be switching over to the hub motor drive.

‘The hub motor is the future’,
Jason Potter said in the video explaining the limitation of belt drive vs hub motor.

With its clean and simple implementation and relatively lower parts cost, it is easy to see why hub motors were adopted so readily by the eskate community. Aided by the fact that most of us are unwilling to deal with maintenance of any sort, hub motors have taken the low to mid-end market by storm. Their quiet, stealthy, and kick-push-able nature only aides in the appeal department.

However, hub motors are not without downsides.

Poorer ride comfort can be expected as for every hub motor, you lose a standard longboard wheel and the urethane that goes with it. The thinner urethane sleeve, the worse shock absorption is, and the worse the ride.

Hub motors also tend to not have as much torque or braking power at similar power input levels. With the exception of specialty designed hubs such as Hummies and Enertion hubs, drive trains with gear ratios fare much better in this department.

To add to that, hub motors generally have a much higher failure rate than belt drives due to how they are exposed to a greater magnitude of shock and heat versus their belt drive counterparts.

Gear Drives

Gear drives are a relatively new addition to the eskate world. The basic idea is that instead of a belt to drive the wheel pulley,  the motor pulley should directly drive the wheel pulley. This preserves the gear ratios and wheel choices available to a regular belt drive while reducing the drag that is typically introduced by the belt.

Sounds like a great solution right? Unfortunately, it does have drawbacks. Direct metal on metal contact from the gears raise concerns that they might wear down prematurely compared to other motor systems.

Low ground clearance also would be a problem.

Gear Drives hang just a centimeter off the ground. Versus their belt drive counterparts, gear drives are more prone to getting gnarred up against the ground and potentially snagging on hazards that the board would normally roll over.

Due to their low clearance, you’re pretty much forced to run overly large wheels to compensate. This makes gear drives pretty damn heavy and undesirable in some cases.

Noise is an issue as well, as gear based drivetrains make a lot more noise than their belt based counterparts. Helical gears attempt to solve this issue, but they don’t entirely and remain untested on a large scale.

It’s also very difficult to get your hands on a gear drive train. With Jed’s product still massively delayed, the only other companies currently offering gear drive eskates are Arc Boards.
It’s possible to obtain a gear drive train from small-scale producers such as E-toxx, and Kaly.NYC, but they usually cost an arm and a leg.

Direct Drives

There is a lot of confusion surrounding the term ‘Direct Drives’.

The proper definition for “Direct Drive” is a system where a full motor directly drives a full wheel. Although both hub motors and gear drives have both been marketed as “direct drives” before, they are not. As of right now, the only commercially available direct drive train is the Carvon.

So far, there were a lot of good things said about Carvon’s direct drive.

• Allows the use of full urethane wheels.
• Allows for easily swappable wheels.
• Allows for free rolling and a quieter system.

While the direct drive seems to be a great drive train, there are still caveats. The motor sits right next to the wheel and is not shielded, so affects ground clearance and is very likely to be battered on bad roads. It typically requires heavy modification to the trucks and is not necessarily compatible with a lot of setups.

Not to mention Direct Drives are extremely heavy.

Unlike hub motors, they use a full wheel of urethane (versus a urethane sleeve). Couple this with motors of equal or larger size than a hub motor, and you have a drive system that is inherently heavier by nature. Another extremely heavy component in Direct drive is the steel axle. The V2 Carvon Drives used an 8mm axle (standard for belt drive and hub motor trucks) that was prone to snapping.
The new V4 drives use a 12mm axle to circumvent this problem. However, this adds a very significant amount of weight.

There have also been reports of significant lack of torque on Carvons. But the most important point is that this is still an extremely new and unproven technology.
Familiarity with this drive train has not reached the point where it might make sense to recommend it.

While different people have different priorities, I still believe that the future of electric skateboard lies in the gear and the direct drive. Hub might have its place for the price, ease of install and maintenance, but belt… with gear drive around, belt drive is probably is on its way out.

My opinion.