Measuring the pulley
Whether measuring crank pulley or supercharger pulley, you must measure across the tips of the ribbed section to make an accurate measurement.
When looking at the speed result in the calculation, it is unwise to run near to the limit, as the heat and wear rates rise exponentially at speeds above 50 000rpm
If you wish to run near the limit, then like anything near the limit, you are near breaking point – meaning your maintenance and belt consumption will rise more than running at a lesser speed