A air propeller driven bike - actually, I'm considering a trailer. The Wright Brothers were bicycle mechanics before they were airplane mechanics, so the concept has been floating around for a while. (Previous discussion in this form is meager.) Endless Sphere thread There are prop venders. I plan to use a cowling around the prop as a guard and to channel the air. Since the bigger the prop, the better, the limiting factor is unwieldiness. I'm thinking the prop can be a meter in diameter. I plan on using the Harbor Freight Predator 79cc engine. I'm familiar with it, and it's cheap (US$80. with coupon and tax exempt). Direct drive: the prop will attach to the shaft of the engine. Trailer hitch will probable be a swivel universal joint at the seat post. Kill switch wires and the throttle cable go from the trailer to the handlebars. I'll use 26" wheels spaced as wide as I can to the sides of the cylinder cowling. A big objection is that air drive is inefficient contrasted to a drive using the friction of the surface for traction. True, but an air drive, particularly a detachable one, has advantages to compensate for the lack of efficiency, simplicity, for starters. Yes, I'll surely peg the dork meter on this one, but, you know, they laughed at Robert Fulton. Fulton's folly Yes, I realize pushing bike trailers are reportedly problematic at higher speeds. I'll deal with this by making the point of attachment as far forward as possible, and I don't expect to go fast, anyway. Since the the Prop-Pusher-Trailer is transferable from any bike to any other, I can't see this becoming a waste. But if it's worthless, I can use the engine elsewhere and I'll have a trailer. Criticisms, Suggestions, Comments, etc.?