Finding an ideal cleat rotation, that being the centreline of the cleat relative to the athletes heel, is best achieved dynamically through on the bike assessment, with application of different levels of torque.
This measurement is a simple one, but should be constantly reconsidered based on other changes made during a fit. Differences in shoe setup, insoles, wedging and saddle adjustments can all influence the stability and rotation of an athlete’s foot during the pedal stroke.
It is very common to see cleats with more float chosen in an attempt to fix discomfort caused by poor position or instability in the foot. Most athletes, with properly considered fitting, do not need any more than a small amount of ‘margin’ afforded by cleat float.
AC Performance Bike Fit 