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Unread Today, 11:07 AM #10
MikeK
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Join Date: May 2010
Location: Windy City
Posts: 2,804
Default Re: changing to 5.50 Bias Ply = changing to 3.54 ratio
One very slight problem with the above calculations- The measured diameter of a tire is not equivalent to the rolling diameter. Even for tires of the same size, this will vary between manufacturers, construction, and tread.

Many tire manufacturers list revolutions per mile for each tire they produce. That is the most accurate way to figure speed vs. RPM.


Mike V In my opinion is closest to correct. However I Think the most accurate is to get the distance from the center of the wheel to the ground with the proper inflation air pressure. double that to get the effective diameter. This will be slightly less do to the weight on the tire. I know this is very OCD but that is just me.