Here is my first instructable. I made this before I joined instructables so there is only one picture of the bike. It all came about when my son decided to dismantle his bike and put smaller wheels on. I had a spare car wheel and so we decided to join it all together. First I had to weld the rear bike wheel to the car wheel, in order to have the sprocket on the rear wheel. Then I fabricated a flat bar frame to hold the car wheel. This was then welded to the rear of the bike frame as high up as possible but with enough clearance for the pedals to rotate without catching on the floor. This gave the dragster look. I then had to join two chains together and shorten slightly to compensate for the longer distance between the pedal sprocket and the rear wheel sprocket.
My conclusion is that gears would have made it easier to pedal on the flat and uphill. Its great for going downhill.