It's What's Inside (your motor) that Counts title=

It's what's inside your hub motor that sets it apart from the rest.


Quality parts and assembly

We've written here before about how to choose a motor, the different types of motors, the performance differences between motors, etc. But today I want to show you what makes our motors different from other hub motors. Today, harry is replacing the axle on a customer's direct-drive motor. The bike was crashed and the axle was bent really badly, but we were able to repair it for them. 

Hub motors from many manufacturers look the same, there's really only a couple basic styles, but once you take the side cover off, you'll see a huge range of differences. Compare the two motors below, for instance - our motor, on the left, uses plastic spacers on the stator, ensuring that everything stays secure, insulated, and at the proper clearances. On  the right, you see a motor built with bamboo spacers. Bamboo is cheap, plentiful, and easy to cut to the right size with minimal tooling. But bamboo expands and contracts with moisture and heat changes, and it's never perfectly uniform to start with. It doesn't fit securely in the stator and the pieces can slip out of place. This can jam up your motor or cause shorts. See how the left-most spacer in the picture has shifted so far out of place? And, since this is a cost-cutting measure, time isn't taken to trim them all to the same length...

Stator spacers plastic

E-BikeKit uses plastic spacers - uniform and durable.

Stator spacers bamboo

Others use bamboo spacers - inconsistent and can slip free.

 

The wire assembly is another place you'll see a lot of differences. It's best to seal the opening with a sealant like silicone. We see some motors not being built this way, though. If you ride in the rain, especially, you want to have that axle sealed up so water can't trickle down the wire and into your motor.

 

wire sealed

E-BikeKit axles are sealed with silicone sealant.

wire not sealed

Others use no sealant, so water can come right in.

 

 

Magnet coating

EPD finished magnets resist rust and don't poison fishes.

If you ride in the rain, you want to have that axle sealed up so water can't trickle down the wire and into your motor. If you do get some water inside your motor, we've got you covered, though. The magnets in our motor are treated with an EPD coating prior to assembly. We used to use chrome-plated magnets, but our factory recently switched to an EPD (Electrophoretic deposition) coating. Chromium is not desirable for a number of reasons - it's toxic and carcinogenic, and can be bio-concentrated, often ends up in the water in industrial areas, poisons fises and can accumulate in the body. It's really only been the last 10 years or so that evidence of the environmental damage caused by chromium has spread, and modern factories are phasiing it out, but it's still being used in lots of places, so we're glad to be getting away from these damaging effects. And on a brighter note, EPD coatings have better adhesion than chrome plating usually does - chrome can flake off if damaged, but EPD based coatings will stay stuck on where they belong.

 

We also use high-quality rare-earth Neodymium magnets. These magnets are more powerful than other magnets so you have more efficiency and torque, and they resist demagnetization, so they last longer. Cheaper ferritic magnets can be found in some motors. Some of our motors have 64 of these magnets, which retail for up to $1.89 each, so you can see why some manufacturers would give in to the temptation to cut costs with a cheaper magnet.

We also assemble our bearings with grease on both sides. Most bearings you see are assembled without grease on the seats, but grease is essential to get a clean assembly - it lets the bearing slip in smoothly so it goes into the correct position, reducing wear and increasing the lifespan. The extra grease at the interface makes it more waterproof and slows rust. Note also that the bearings are sealed on both sides, not just shielded, and the axles have shaft-seals to add an extra level of waterproofness.

shaft and seat bearing grease

The shaft and bearing seat are greased before assembly.

bearing grease

The inside of the bearing is also greased.

Additionally, wires are routed carefully and covered in chafe guards and zip-tied in place to keep them from being worn by spinning parts in the motor.

chafe guards

Chafe guards and wire ties prevent internal damage.

winding

The stator is carefully wound and varnished. a plastic spacer prevents shorts and damage.

 

So remember, it's what's inside that counts - details of assembly and the quality of the parts will have a big impact on the quality and longevity of your electric bike conversion.