Hey deacan, It's very hard to put into words but an air filled small rubber tire works great as a "friction drive" I have done it and it NEVER spins or wears bald spots into your tire. I used a 8 inch tire with sprocket attached. Have you ever noticed that most rides use this method at your local fairgrounds! If you face the engine towards the rear, you don't have to worry about jackshafts and running backwards. It's not as foolish as it may sound.