Seeking DD motor, wanting selection and opinion

[Chalo]

I am hoping to find something made in the USA or at least some place that doesn't involve slave labor or wage slaves or whatever you want to call it.

I suspect you don't have any options for a direct drive bicycle hub that isn't Chinese made. For what it's worth, Crystalyte looked like a family-run cottage industry type operation according to photos and reports from Todd Fahrner's trip there a few years ago. Ladies sitting together around a kitchen table winding armatures and so forth. They may be low-paid but they don't have sweatshop conditions.

Outfits that produced much larger quantities for the home market are where you'll see more traditional factory conditions. Crystalyte seems to be focused on the export DIY market.

 

[RICK]

re 9c disassembly - FWIW I popped off one side cover, then made a handle out of a piece of flat stock with a hole drilled to accept the axle, had two guys hold the rim and just pulled the stator out by hand. The bearings are not in the housing real tight, just a light press. Then again I had access to a full shop.

If this sounds like a pain, maybe justin and crew at grin would do it, from their website it looks like this very easy for them. That way it would be turn-key. Kind of wish I'd asked them about the service instead of doing it myself..

On my first build I had good luck with John Rob Holmes (Holmes Hobby) lacing a 9c into a good rim..

 

[chilledoutuk]

Honestly 9C motors rock IF you look after them properly.

What that means is :

- Not running more than 1.5 to 2kw peak with the stock phase wires. (make sure motor is no more than warm to touch after ride)
- Use Decent torque arms
- Run a drip loop and keep the bike somewhere dry if you haven't protected the stator as mentioned below.
- Run 2 inch tires like the 2 inch scwalbe mararthon tires to absorb impacts better.

Protecting the stator

Biggest problem with all Hub motors is the stators vulnerability to oxidization as the metal they use is bare magnet steel and will rust with any amount of moisture.

Accepted Way
The accepted way of dealing with this is to dismantle your motor and spray the stator with a protective coating and then perhaps drilling some vent holes in the motor cover to allow the moisture to evaporate.

My Way
My way of dealing with this however is to drill a small vent hole in the side cover whilst the motor without disassembling the motor this is easy to do but you have to be very careful i positioned the drilling site so that it was away from the phase wires and drilled in a location that the only thing i could hit would be the pressed steel holding the stator to the axel.

you then drill the hole very carefully with something precise like a dremel with a attachment that limits drilling depth to just a little more than needed to get though the cover and keep checking and blowing out loose files in the hole and on the bit. When you get close to going through the other side of the cover gradually cut the hole on a high speed to keep the filings size as small as possible. Remove the bit and use some sticky tack to grab any filings still in the hole.

Now you have a vent hole in your motor that moisture can escape through but also a access hole you can use to put an anti corrosive spray on the insides of your motor with. I use ACF-50.

If your worried about the aluminium files getting into the motor remember that the size of them will be small and that they are aluminium VS steel they will simply just get mashed into the lamination stack.

 

[bowlofsalad]

Thanks Parajared, Davec, Chalo, Rick, and Chilledoutuk.

@Parajared Did you ever try out a UST rim for tubeless? I am lost to rim selection, there doesn't seem to be much of a definitive guide on the subject, the only thing I know for sure is downhill double walled rims sound like good phrasing to look for.

@Rick Did you mail your hub to John Rob Holmes? That wasn't prohibitively costly?

@Chilledoutuk I certainly plan to do everything you mention. I've done a lot of reading on the subjects of failures and problems of motors and ebikes in general. I feel like there is a lot of things that can be done to make a motor much more reliable for short and long term. I guess it sounds like it doesn't matter too much for which motor you buy, just so long as you set it up right. High air volume (fat) tires interest me a lot. Right now my plan is to use a 622x60 (28x2.35) schwalbe big apple tire, and I am starting to warm up to the idea of using tubeless with this tire.