Go high tech.
I'd take a military folding mountain bike with tubless rideflat tires and a removable gasoline engine capable of going > 50 km/hr.
Get the bike from:
http://www.militarybikes.com/para.htmlGet your engine from:
http://www.fiveflagsmotorbikes.com/BicycleEnginesGasoline.htmGet your ride flat tires from:
http://www.airfreetires.com/Default.htm-NIM