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Old 06-19-2013, 03:03 PM   #19 (permalink)
gone-ot
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Quote:
Originally Posted by wolydotmatrix View Post
Does the outter diameter actually change? Does the tire just touch more ( or less) of the road. A ballons circumference will change due to its phisical properties. Does the total circumference change or does the tire just become more round?
Q: Does outer diameter actually change?
A: Yes!

FWIW, the "loaded" tire diameter (what you'd use to calculate tire-revolutions per mile) is typically about 0.97 of the tires un-loaded diameter (my analysis of Michelin and Goodyear tire data)

But, the amount of diameter INCREASE from higher airpressure is MUCH smaller due to the constricting force of the steel belts (<0.03).
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