Originally Posted by Dan
Would make an awesome pusher. Especially on a bike you want to keep in original bicycle form.
That's what I was thinking too... Someone could put the engine on the tag along then they could convert any bike they own at any time. The throttle could be converted to throttle by wire using an RC servo so that would make it even easier to move from one bike to the other. The centrifugal clutch kit and a pull starter would make it even more convenient, and it could be added as a second engine to one that's already motorized for better acceleration or hill climb ability.
As far as stability goes, a utility trailer might be a better idea tho, but anything could be made from something like this to fit one's needs.