Posted by Keith in Washington [108.162.246.122] on Sunday, December 23, 2018 at 20:08:51 :
In Reply to: Re: 4.89 gearing posted by Mannyc [108.162.219.187] on Sunday, December 23, 2018 at 16:49:55 :
Radius is equal to pie*diameter or 2 * pie* r. So realizing rolling diameter is a little less than the diameter but I ignore this difference as it affects both tires about the same. Looking at Michelin 9.00 and 11.00 tires their diameters are just under 37” and just under 39”. The percentage difference between 39 and 37 is about 9.4%. The percentage difference between 4.89 and 5.83 is 8.4%.
The tire change gives you about 1% more in RPM drop at any given speed. It is really a wash as you will never be able to tell a 1% difference.
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