The 2014 Dynamic Shaft Fitting Addendum is Now Available

Jeff Summitt Then and NowBoy, do I feel old.  I just realized that the on-going independent research on shafts I have been working on has entered its 25nd year!  This shares a silver anniversary with of all things the World Wide Web. And to think of it, I had hair back then – a lot of it.  If you are not hip to what all the fuss is about, it marks a small footnote in history that started to get us out of the Stone Age of how golfer’s choose shafts and begun doing so much more scientifically. This was the first shaft-to-shaft study using the same set of testing procedure to see how golf shafts compare after they have been cut and installed into heads on a grand scale.

What Type of Information Will You Find?

For those that are not already familiar with the Dynamic Shaft Fitting Addendum, the first thing you will find out is not all R-flex shafts are created equal – that is in terms of flex, torque, bend point, etc. as every manufacturer are their own standard.  In reality, there are no industry standards for shafts and the reason why this book serves as an invaluable guide.  Consistency has been the key to this text as each of the well over 3000 shafts and 50,000 measurements has been conducted by one individual (yep, yours’ truly) using the same set of procedures and equipment for these past 25 years.

Dynamic Shaft Fitting Index Table 1

There are 19 published specifications listed for each shaft that include:

Flex, Uncut Shaft Weight, Tip Diameter, Butt Diameter, Uncut Shaft Balance Point, Cut Shaft Balance Point, Completed Club Balance Point, Total Assembled Club Weight, Head Weight, Grip Weight, Cut Shaft Weight, Completed Club Frequency, Butt Deflection, Tip Deflection, T/B Ratio, Cut Shaft Torque, Raw Shaft Torque, Club Length (and wood bore type) and DSFI (Dynamic Shaft Fitting Index) Rating

Some of the specifications may not be important to you or only help you with assembly such as knowing how much head weight you can expect at a specific length.  In other cases, there are several key parameters as shown in the following table which can be considered the shaft’s DNA.

Nuts and Bolts of the Text

If you don’t want to download all 192 pages of this text, I would highly encourage you to at least access Chapter 1, which provides the legends of what each of the specifications are and we would encourage you to read that carefully.  Chapters 2 and 5 are the nuts and bolts of the Shaft Fitting Addendum with Chapter 2 showing the data and Chapter 5 providing the how to use the information with the master shaft fitting charts in order of stiffness.  Chapters 3 and 4 provide data on shafts that are no longer available, but is still a valuable guide to cross-reference shafts.   This year we have added shafts from Aerotech, Graman and Mitsubishi Chemical to the mix.

Dynamic Shaft Fitting Index Table 2

> CLICK HERE TO DOWNLOAD THE DYNAMIC SHAFT FITTING ADDENDUM