I had always known that there was no standardization in shaft stiffness’s from one manufacturer to another but felt that within the specific companies there would be a standard for these designations. In my recent work with The Ben Hogan Golf Co. to set up their Club fitting system using a wide variety of shafts, I even found this to be wrong. The following table summarizes the difference in the natural frequency of the various designations in the products of several Manufacturers.
Natural Frequency Deviation in Cycles/Minute – cpm by Manufacturer for X, S and R shafts
Shaft Stiffness X S R Manufacturer 1 51 50 41 Manufacturer 2 10 63 80 Manufacturer 3 6 23 24 Manufacturer 4 23 17 23 Manufacturer 5 13 22 Manufacturer 6 20 19 Manufacturer 7 24 14 8 Variance Low to High in group of 7 51 84 85
Understand that if you are told you need a stiff shaft for your swing, to get the right one from this group of manufactures, you are searching in an low to high range of 51 cpm. What does this mean? To get a fit that will give you your best distance and accuracy we have found you must be within 4 cpm of the correct natural frequency to fit your swing timing. It is up to the fitter to pick that shaft for you but he must know your natural frequency requirement and frequency of that shaft when built into the club assembly. Trying to get the correct frequency by just knowing you need an R, S or X is hit and miss and we can see why it is mostly miss if you do not know the exact frequency you need. Using Frequency as the designation is the most accurate way of designating club stiffness and does not change from manufacturer to manufacturer. This is the fitting system developed by Perfected Golf Group, Ltd. for The Ben Hogan Golf Equipment Co..