Originally posted by bigwalton:
Ooops, I didn't notice the second page on this thread, but my last reply still holds.
lol
[b]tboner, to answer the question it looks like you will ask, I called the tire effect negligible because of what you said about the weights being very close and the distribution of weight in a tire. What I mean is that the vast majority of weight in a tire is not sidewall, it's all that rubber and belt that's on the road, and since I'm assuming negligible differences in diameter the overall wheel/tire combo, that weight is in about the same place, 16 or 18.
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I'm not quite sure if you're referring to just the example I gave using those specific tire attributes or just in general. The tire effect cannot be considered negligible when comparing inertias, if for nothing else, because it contains pressurized air. Even if a 16" and 18" tire have the same outer diameter they will have different volumes of air contained within them.
Ok, about this air pressure/sidewall thing. I can guarantee that the sidewall is only designed to deal with cornering forces, road generated forces, etc. Holding air is not on the list of worries that they are going to have. Have you ever seen high pressure hose? Heck, look at your garden hose, it's dealing with 30 or so psi and it's thin as hell! So 30-50 psi in something like tire rubber ain't no big deal.
I agree to a certain extent here. Tires will rupture at a certain pressure, though, and it's not 3-4 times the max pressure suggested by the manufacturer. So I think there would be a point when the sidewall becomes too thin at certain points (particularly because of the expansion of the tire upon pressurization).
