Originally Posted by
Atlas Shrugged
Thanks for the correction, and I agree that it is not a linear response when narrowing the rim dimension. I would love to see the actual numbers. In my own experience, when using a very supple tire and wide rim, the outside diameter went down noticeably. The image provided proves nothing and is based on the theoretical response of a tire when placed on various rim diameters. ....
Like you, I dislike computer generated images because we never know what assumptions were factored into the calculations. My reference to a circular profile relates to the unsupported section of the tire, based on a typical Omega profile. As rims get disproportionately wide compared to the tire, the constraints near the rim will distort the profile to a greater extent forcing the tire to a more U'shaped profile, but the rules still apply in the free section, which will still form an arc of constant radius.