This Racers Leading Edge screen is a pair of calculators to help optimize your tires/gearing. For example the calculators allow you to change gearing or tire sizes, and determine the effect on your engine's RPM's. Simply enter your known information, i.e. Tire Circumference, transmission gear, rear end gear and MPH in the left column. Leave the RPM column blank and select calculate and the RPM answer will appear in the right column with a yellow background. This information can be saved for either calculator. Upon opening the calculator, the save information will be displayed for both calculators. Enter values in 4 of the 5 columns on the left, the answer will be calculated for the blank column. Each calculator has an example which is shown on the screen above.
Note: Tire Circumference (roll out) is in inches. Rear and transmission gear are expressed a decimel number i.e 3.55 = 3.55:1. To obtain the decimel number, divide the number of teeth on the pinion gear into the number of teeth on the ring to get the decimel number. i.e. 44/9 = 4.88