Hello. I used to drive trucks and can see why a bike, especially a small motorized bike, could make things way easier when you're stationed or broke down.
(inexpensive folding bicycle)
Dax Friction Drive kit.
Also, there is Staton Inc (not quite the same design, but also a heavy duty friction drive, and US made. )
You should be able to get it all together for $600.
Skip the chinese in-frame engines and "motorcycle" looking stuff if you want to haul it along on a truck. Save the sweet starting weeder engine for your yard.
Dax Friction Drive Fan Club for more info
Ride video from my Dax w/33 cc tanaka (just idling along with the fat roller, on road bike with fat tires)http://www.youtube.com/watch?v=lr39-x0j0zQ