How does the geared hub motor work?

[Wes Turner]

It is my understanding that the C380 uses a geared hub motor. The sales person showing me the bike tried to explain it to me, but all I got was that it's a system of floating balls, or something.

Can someone explain it better?

How does it compare with a manual gear system with multiple sprockets in front and back?

Are there any problems with the geared hub system that are not present with the manual gear system?

Thanks

 

[Stefan Mikes]

It is my understanding that the C380 uses a geared hub motor.

Not. The Gazelle C380 uses a modern mid-drive motor that is located where the bottom bracket would be on a traditional bicycle, that is, where the cranks and pedals are.

You actually rotate the crank through the motor. Your combined leg power and the motor assistance act on the "chainring", which in the case of the C380 drives the carbon drive belt (instead of your usual chain). The drive belt acts on the sprocket in the rear wheel, and that sprocket drives an IGH (Internally Geared Hub) gearbox. The power delivered by your legs and motor eventually goes through the IGH transmission to rotate the rear wheel of the e-bike.

This solution is very modern and requires almost no maintenance from your side. The mid-drive motors are very efficient, are excellent climbers, and make the transmission amplify your combined leg + motor effort for climbs, or, on the opposite let your e-bike ride fast on the flats, depending on the gear you have selected with a gear selector near to the handlebar grip.

The geared hub motors drive the rear wheel directly and are independent of the drivetrain. Geared hub motors are found on inexpensive e-bikes.
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The mid-drive motor, the carbon belt drive, and the IGH are typically found in so-called SUV e-bikes, such as the Gazelle C380. Normally, a chain e-bike with a mid-drive motor has a similar motor as found on the Gazelle C380, only the pedals/crank operating through the motor drive a real chainring, which is a single sprocket. The chainring drives the chain, and the chain acts on the cassette sprockets that in turn drive the rear wheel. The gears are selected by the rear derailleur.

This modern drivetrain is called 1x because there is only a single chainring in the front but many sprockets in the cassette: from 9 to 12. The 1x system has got rid of the complexity related to the front derailleur, and is good for mid-drive e-bikes.

Have I made it too complicated?

I think you got confused by the "Internally Geared Hub" (a gearbox) and the "Geared Hub-Drive Motor" (a motor).

 

[Viking1]

The 380 is a VERY good choice! Do your homework in advance of purchasing and then having buyers remorse. Gazelle makes an incredible product to boot.
Welcome to the forum!!

 

[indianajo]

This gazelle 380 https://electricbikereview.com/gazelle/2023-avignon-c380-hmb/
court reviewed does not have a geared hub motor. It has a bosch performance line mid drive. The enviolo rear hub is variable speed. It has two tapered shafts with a couple of balls between them. The position of the balls determines what the speed up or reduction ratio is. The cable & cage move the position of the balls. The gates belt drive avoids the problem of mid-drives of wearing the chain 2 to 5 times faster than a pedal bike with same width chain.
The bosch mid-drive cools better than equivalent power geared hub motor. Geared hub motors have an air gap between the windings and the case, inhibiting flow of heat out of the motor. Thus mid-drives can climb long slow steep grades better than geared hub motors. They can climb slowly for more time before overheating.
Bosch motors are fine for people that do not want to exercise much. The bottom 3 levels drag the motor with the feet if the rider pedals unpowered. Some people ride farther & faster on mid-drive bikes than they would unpowered, thus achieving their aerobic goals. Only 5 miles on the level, a rider would not get much exercise.