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Old 03-09-2018, 09:22 AM   #27 (permalink)
CapriRacer
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Quote:
Originally Posted by davelobi View Post
Tread depth between a new and a used up tire definitely makes some difference in both the outside diameter of the tire (unloaded or loaded) as well as the radius from axis to patch on the ground. Take the drawing and then add one half inch more rubber to the tire tread. This instantly adds one half inch to the radius and pi x radius squared to the circumference. With pressure and load constant, this new tire will roll further with each revolution than the identical tire with less rubber (smaller circumference). Tire patch is not affected.
But as we have already established - at least I have in my mind - the static loaded radius doesn't relate to the rolling diameter AND the idea that there is some connection between some physical dimension (and pi) and the rolling diameter isn't valid either.

While I think there is some effect tread depth has on rolling diameter, I don't think it is as large as is being portrayed - and it is not the dominant factor when it comes to RR as a tire wears.

What I think we need here is someone actually measuring how a tire behaves as the tread wears out. Anyone have access to a tire shaving machine?
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