Awesome German rim motor concept

[quuxman]

I was just poking around looking for a rim friction drive motor like the Velogical Velospeeder that you could ideally actually buy and wasn't god awfully expensive, when I came across yet another unavailable concept that's even more awesome, and even more expensive.

It's a motor built into the rim and frame, with permanent magnets on the rim, and the coils along the "down tube" which is curved around the rear wheel. See pictures here:

http://evbud.com/news/306/

I can easily see this being the future of high end ebikes. Seems like you could get lots of torque yet still attain very high speeds due to it being direct drive, while also keeping it ridiculously lightweight with very little extra material for the motor. This seems mighty ingenious. Has anybody else seen this? Any thoughts on a DIY version? . I could also picture a more-or-less drop-in product which is the rim and a bolt / clamp on version of the coils. How is this not the best of everything?

 

[Thud]

Hehe,
I saw this concept about 4 years ago when arlo1 was building one for his bmx bike.
Have to search for the deeply burried thread.

edit: Make that 6 years ago:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=9966&p=155729#p186562

 

[Doctorbass]

bike is nice,,, but again.. they anounce 100km/h with a 500W motor ... witch is way not enough!!! and.... I M P O S S I B L E for a bike like that!!

it's like saying my bike with 16kW could go 1000kmh... well maybe in the vaccum of space!

Doc

 

[Dunkenb]

Think it said it was limited to 500w/ 45kph so as to be legal with the potential for more up to 100kph

 

[Doctorbass]

Think it said it was limited to 500w/ 45kph so as to be legal with the potential for more up to 100kph

For 100km/h you need AT LEAST 6000W on a bicycle.. inless you go down hill on the TOUR DE FRANCE.

I just Wonder how they think they can tune it to that power... 500W to 6000W that's a 120% boost...

Also i hope they use 100C+ LIPO because the size the bike have to store battery is limited and a battery capable of 6000W of that size require that kind of C rate...

Doc

 

[e-beach]

The roads must be clean in their city. Around here the junk pieces of metal, nails and bolts will be waiting to shred that poor rim.

 

[rsilvers]

Yes, it is a bad concept. Not only will it collect scrap metal, but the alignment will be hard to maintain and mass is better kept in the hub.

 

[quuxman]

Hah, I hadn't thought of the rim picking up metal scrap. That's a good point, and with the half exposed motor, any metal that stuck to the rim could damage the coils.

 

[ewinters]

Made me laugh hard now, a bike that throws bolts and nails to the back of your head...