Calculating Driveline Revolutions per Minute (RPM)
Tire diameter is measured from the ground to the top of the tread.
Gear ratio is ring turns to one pinion turn. The pinion shaft is 1:1 with the driveline.
The tubing diameter of a driveline must be sufficient to handle the RPMs it will be turning.
There is a "length limit" to all tube sizes at which point the driveline reaches "critical speed".
Exceeding or approaching the lenght limit will cause vibration - even IF the the driveline IS in perfect BALANCE !
< See Dana's guide to safe operating RPMs. We recommend operating at one half critical speed. >