Double Bike Takes You on a Supremely Ridiculous Ride By the looks of things, this double-wheeled bike concept can easily stand alongside gems like the 12-foot tall bicycle , face to face tandem bicycle and the running bicycle in terms of sheer stupidity and pointless danger. Since there is no chain attached to the lower wheels, I can only assume that the upper wheel is generating all the momentum—transferring the energy like a set of gears (although, I can't imagine that would be very efficient—and you would have to pedal backwards). At any rate, you would have time to think about how stupid this all is as you hit a pebble in the road and fall to your untimely death. [My Confined Space via Coolbuzz ]