Gamorg. I have a 2 x 4 with a piece of carpet on it. I just put it inbetween the tire & the rubber pad. It works great. If you space the rubber out it might be to far out when you do big tires like 240's that is why I just stick with the 2 x 4. Your gonna be in for a challenge the first 200-240 you do some of them can be a pain. I got it down to an art now but you will cuss with the first few.