History and results show that larger diameter rims (not tires) tend to be an advantage in both real and scale racing. Going back many years when Yokomo surprised many other teams at the offroad worlds with 2.2 in rim (standard was 2")", it was a huge advantage prompting some teams to scramble to make rims larger during the event. In most racing applications, you will find that the wheels are built to the max specs allowed by the rules.

Also, the overall diameter of of the tire is really not the key, we believe that the sidewall size is more important than the overall diameter. For most grip conditions experienced in road racing, small sidewalls give the car a solid planted feel that a large rubber-to-wheel ratio (tall sidewall) will not give. We feel that a 40 mm tire on a 38 mm wheel will out perform a 40 mm tire on a 37 or 35 mm wheel. IMO, the 40 mm size mentioned is not the key or the target, it is the tire size relative to the wheel.

Obviously, both sizes have won many races, so this is more grey than black and white, but if small wheels are as good as large wheels, why aren't we using the old 1.4 (35 mm) rims from the old days? The reason... bigger is better. (pun intended) :-)

My good friend and racing teammate, Terry Rott has been bugging me to make a 1.2" wheel for many years. He enjoys harassing me about it every chance he gets in a joking manner. I suppose there are some occasions when the small wheel would be better, but history shows big wheels and small sidewalls make fast lap times. That is why we designed CRC rims to the max dimensions of the rules.

Sizes we normally run...
Speaking for the Rome, NY based drivers, Brian Wynn and I usually start at 1.63 (~41.4) fronts and 1.67 (~42.4) rears. Most of the time at large events, by the 2nd or 3rd round we end up running about 1 mm smaller. Tom Firsching has had some excellent results with larger tires, 1.65 front, 1.70 rear. Similar to Tom, John Firsching and Mark Calandra tend to run larger tires as well.


Frank @ CRC