What a crazy contraption. Interesting that they would attach it to the existing wheel. I seem to recall that when I was looking into electric hub motors for another project concept that would have potentially used bicycle wheels, there where concerns of putting too much power onto spokes designed to handle the load from a human cranking on the wheels, not a 4-stroke gas engine!
That definitely would not be street legal here in Ontario, Canada.
It's an interesting idea though, but it raises questions, in my mind:
- Will the wheels hold up under such power?
- Will the brakes be able to stop you with the added weight/velocity?
- It's mounted pretty high up in the back. How bad is that thing to balance?
- How safe is it to have a gasoline engine right behind your butt? Wouldn't that cause burns, or risk fire to the seat/rider once it gets hot? I remember working with gas-powered lawn mowers. Those little engines get hot enough to cause a bad burn after running for a little while.
Back to the spoke thought - Wouldn't that big ring, attached to the spokes as it's shown, be applying a fair amount of stress in the middle of the spokes? That sounds like a bad idea to me - betcha it snaps 'em like nobody's business.