What about the Hobbyking RC motors?

[Arbol]

I have been impressed by this build:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=54557

apart from the carbon fiber, he says he is using a Hobbyking RC motor:

https://www.hobbyking.com/hobbyking/store/__17987__Turnigy_RotoMax_50cc_Size_Brushless_Outrunner_Motor.html

and by looking at the specs, it seems spectacular: in 1kg, about 5kW! and mostly from amperage.

I guess these motors are intended to impulse low weight vehicles, like RC airplanes. But I guess that if one has a light weight bike, it makes sense to consider them.

Has anybody tried / thought about these motors?

 

[trex]

it is difficult to predict without a motor test report. The potential is there, but you need to take into account that on average, you only need 250W out of a potential 5KW output. The yield of the motor could be quite low if the motor spins at 320 RPM instead of 6400 RPM as at its maximum output. You would end up with a light but very inefficient drive system. You still need to find / build a clutch and a reduction gearbox.

 

[Deleted member 4366]

Throttle response is not so good, but they work.They have a very high power to weight ratio.

A guy on ES did a nice Dahon Jetstream conversion with one and a reduction system

Also, check out Kepler's commuter booster:

http://www.commuterbooster.com/home

 

[amigafan2003]

They are also super loud, so don't use one if you're looking for stealth.

Have a listen