I thought this was pretty cool, since it uses your own cordless drill. Because of that, you could carry more than one
battery for extended range. they claim 4 mi range on a regular 18v cordless
battery, but I have 8 of the Ryobi Lipo
batteries, quite a bit more powerful than the standard battery (advertised as 4x capacity.)
The bike in this video doesn't have pedals, but it can be installed on a bike with pedals since it has a one way
clutch allowing it to coast or be pedaled.