Different grips can effect a clubs c.p.m.by as much as 6 counts, effectively stepping a shaft.Is it possible this can change the way the shaft works ? Could fitting a softer grip be an alternative to soft stepping ?
I have been involved with Frequency matching from the beginning, over 30 years ago. From the beginning, if you measured frequency with a grip on, the number could be affected by the grip. The grip size, the grip type (cord would read different than rubber), would give you different readings. One frequency machine we used had two marks on the clamp, one for standard rubber grips and one for cord grips in an attempt to get the readings to be the same. Rubber grips were clamped 5 inches and the cord grips about 4 inches. It was just an attempt to manipulate the numbers so that the difference in the firmness of the grips was accounted for and the numbers fit the flex designations on the chart. In hindsight, in my opinion, all of the charts should have been set up to show the flex ranges without grips. However, the selling point at the time was to measure clubs with grips on them, show players how inconsistent their set was, then re-shaft them with “frequency matched” shafts. More than you wanted to know, I know, but the point is grips do not effect the flex of the shaft. They may effect the reading of a frequency machine, depending on the clamping dimension, clamp pressure, etc. but they do not effect the flex of the shaft. My suggestion if you are going to use frequency as a reference, is to check them without grips on them. The goal is to have the right progression of flex throughout the set. If your using a frequency chart, the flex designations are probably based on “grips on”, so the measuring with grips off will make the shafts appear to be not the right flex. If you can assume the flex is correct from the shaft manufacturer, measuring without the grip will identify the progression of the set and the consistency of the flex in the set.