Comment by arjie
1 day ago
Haha, I like all these adapter designs though my favourite was the Copenhagen Wheel[0]. I saw someone ride one near Mission and S Van Ness and loved it. Sleek device. This particular one in the OP is definitely built for safe societies, right? Definitely not for the North American market, haha!
Basically, the Copenhagen Wheel moved all the complexity of setting up a hub motor drive system - motor, battery, controller, sensors, computer - into the hub shell itself.
Which made it seem neat and clean, but meant it had serious reliability issues, couldn't handle wet conditions[], wasn't really repairable, and was expensive compared to more reliable alternatives with better battery life, etc.
[] The manufacturer apparently stated that "[...bad bearings] can occur when the Wheel is repeatedly exposed to wet conditions. Due to the nature of the problem, this cannot be repaired": https://forums.electricbikereview.com/threads/known-issues-p...
Psst, you can escape an asterisk [*] with a backslash.
Hub gears work quite well though don't they? In particular respect of being sealed and protected from the weather. Unclear why there's an opposite effect for this wheel.
Thanks - I'd have to have noticed that I used an unescaped asterisk first... too late now.
Did you mean hub gears or hub motors?
The Copenhagen had an ungeared hub motor. Comparing it to other hub motors, theirs was only IPX4-rated, which is basically splash-proof, not waterproof. Decent hub motors are IPX5 or 6.
On top of that, when your hub motor leaks and bearings seize up, fixing it is typically simple and cheap. Pop in a new bearing and new seals and you're done. Most bike shops can do it. With the Copenhagen Wheel, the manufacturer's advice was to throw it away.
The waterproofing rating seems to have been a design decision they made to simplify the design, keep costs down, etc. Since it all had to be custom, they couldn't benefit from the decades of experience, millions of units manufactured, and standardization that hub motor companies like Bafang or Bosch rely on.
See the page about it by the company that actually designed the wheel: https://www.mistywest.com/posts/project/copenhagen-wheel/ :
> "MistyWest had to work around the constraints posed by fitting a heat sensitive component next to a heat generation component in a closed system that allows for very little heat dissipation. The engineering team’s understanding of thermal physics enabled a stable battery system to be designed and adopted for the smart wheel. The inventors of the wheel were the first to ever fit a motor and a power source into a fitted bicycle wheel."
It was a challenging level of complexity. Even if they'd had more funding and stuck with the product, it's hard to see how they would have made it efficiently repairable.
It seems to me that the fundamental issue is that almost every other design is preferable from an engineering perspective. The only attraction of the Copenhagen Wheel was that it made for a quick and easy drop-in upgrade. But at the $1500 price it sold for, you can now buy a whole, much better ebike.
(As for hub gears, they're sealed and filled with oil, grease, or traction fluid, which helps keep water out.)
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It went on sale in the US before the EU. Did you even skim the wiki page you linked?
I see. The way I spoke made it seem like I was talking about the Copenhagen wheel with the phrase “this particular one”. I was talking about the OP device. Obviously since Mission and SVN is in the US I would have assumed it was not the CW but I can see that I was unclear so I have clarified. The Copenhagen wheel is pretty integrated. This one is a thumb screw and off you run with a valuable battery. I wouldn’t buy it here and I bike every day in the city.
People who don’t bicycle in North America won’t quite get it. It’s not exactly Taiwan. Theft is rampant and it’s societally sanctioned in most major cities.