- Local time
- 7:07 AM
- Mar 14, 2011
- Rockwood, TN
My method is to get true tire diameter. Place the fully inflated tire perpendicular to the ground use a level at the top of the tire and measure to the ground. My Kendra 838's fully inflated true tire diameter is 26.25". Then you can use my MPH speed formula.To be a bit more accurate use the tires circumference. Its easy to do with the roll method of making a mark on the tire and floor rolling one revolution making a second mark and measuring the distance. Tires of the same size will vary.
(RPM x Wheel Diameter x π)÷(1056 x Total Reduction)=MPH.