The Advantages of a Small Hub Motor For Wheelchairs

Engineered specifically for wheelchairs, this hub motor replaces the standard wheels and provides a simple bolt-on upgrade. The power and data cables exit only one side for clean frame integration and easy maintenance.

This hub motor uses sealed bearings that protect against grit and grime. Open bearings would destroy quickly in hub motor duty.

Power

The power of a small hub motor comes from a large number of high strength neodymium magnets in a relatively compact shell. This gives the motor a great torque density but it also makes it heavy – this is why hub motor E-bikes tend to be heavier than traditional bicycles.

Typically, hub motors are controlled by a motion sensor on the pedal crank. The sensor senses you are pedalling and then switches the motor on so that it can assist you – as soon as you stop pedalling it shuts itself off.

Most factory resticted hub motors are limited to 750 watts or so – this is to stay under federal power-limit laws and minimize the companies liability should you get pulled over by a cop. However, almost all of them can be hot rodded to run much higher power. The key is to air cool the motor and install a watt meter (like Cycle Analyst) so you can monitor temps – most of these can be tuned to throttle back when they are getting close to overheating.

Some manufacturers even use a twin hub motor system to achieve very high power and torque. These are the types of E-bikes that you see advertised to take you up the most extreme hills with minimal effort – though they still require some effort at the highest settings.

Efficiency

The mechanical efficiency of a hub motor can be pretty bad at low speed. If small hub motor the motor isn’t spinning at a high enough RPM to overcome the forces pushing back against it, its efficiency can be essentially zero (zero electrical in, nothing mechanical out). That’s why those little watt meters on the top tube of some ebikes show such an unimpressive number.

The good news is that a properly tuned hub motor can be very efficient up to a point. They are usually rated at their peak power speed which is when they will be most efficient, and then the power output rapidly decreases as you go faster. That’s why a hub motor is a poor choice for steep hill climbing, or even cruising up moderately steep hills.

Hub motors also draw more current to produce the same amount of torque than mid-drive systems, and this extra current heats up the copper windings. It’s the law of physics that more current equals more copper heat, and it’s a big reason why ebike hub motors generate so much more unsprung weight (weight not held up by the suspension).

One way to increase the efficiency of a small hub motor is to make it larger in diameter. This can help with the magnetic losses and winding resistance, but there are mechanical complications in making such a system work within the wheel space limitations.

Torque

When you’re riding on uneven terrain, a small hub motor can really help out. It churns out tons of torque for easy climbing and traction even when you’re not pushing hard. That extra power also helps you stay in control on steep pitches.

Torque is a measurement of how hard something turns, and it’s measured by force times the distance of the lever arm that twists it. A good hub motor will produce a lot of torque for small hub motor wholesale its size, but you need to be careful how much you use it to avoid heating up and potentially damaging the motor and controller.

Our motors are built for efficiency with a special rotor design, precision motor winding and smart controller. Multiple speed sensors inside the motor report rotor position to our smart controller so we can tune it for maximum efficiency and smooth power delivery.

An internal 5.16:1 gear reduction multiplies the modest motor output to generate plenty of wheel torque. That massive low-end torque enables you to climb hills that would otherwise seem impossible, and the smooth power delivery eliminates surges that can break traction off-road.

Range

When buying an electric bike many of the riders have one big question: “How far will it go on a charge?” This is where a hub motor is able to impress. Hub motors bypass virtually all of the mechanical losses like clutches, transmissions and axles that are found in other drive systems. These components can drain 15 to 20% of the power that’s put into them. Hub motors also do not rely on the tire for torque transfer meaning that they have a better torque-to-force-on-the-ground ratio than mid-drives, allowing them to use even more of the battery’s potential.

With a geared rear hub motor such as the Bafang G31X series or Shengyi SX series you can ride at a moderate pace with the motor ‘on’ and still reach a top speed of around 20mph. This makes the bike ideal for urban and suburban riding where you may want to get to work or just go out for a casual spin.

This motor features a wide 7.77:1 gearing ratio which multiplies the motor’s torque by the wheel speed, making it great for overcoming hills and ripping through technical terrain. The internal hub gearing also reduces noise and vibration so the motor is barely audible at all while riding. Additionally the hub motor shaft features only one exit point for clean frame integration. This means that no wires are dangling and that the motor can be removed from the wheel quicker for maintenance.