Shaft Bend Profiles

One of the things I’m working on now with studying equipment and clubfitting is called ‘Shaft Bend Profile.’ In fact, I plan to purchase Wishon Golf’s Shaft Bend Profile software program sometime in February.

Now, I’m not quite familiar with all of the history of equipment and clubfitting. But, from my experience and knowledge shaft fitting did not get out of the archaic stages until about 15 years ago. And even then, it has still been flawed and imprecise.

Before the 1990’s, most shaft fitting was based on clubhead speed. Companies would assign shafts in either ‘regular flex’, ‘stiff flex’ or ‘X-Stiff flex’ and more often than not, golfers would just be fitted based upon how far they could hit the ball. Furthermore, the Quality Control of golf shaft companies was questionable during these times and often times their QC for the flex of the shaft came down to weighing the shaft. For instance, an X-stiff steel shaft may have been designed to weight 130 grams whereas the Stiff flex may have been designed to weigh 115 grams. Thus, if an employee is checking the shaft weights of supposedly X-Stiff shafts and gets one at 128 grams, they would often times just keep it as a ‘X-Stiff shaft.’


Eventually, Rifle golf shafts came out and they tested the frequency of golf shafts. They would measure the frequency of a shaft and then get each shaft in the set to have the same exact frequency. Here’s a video of explaining some of this:



This was certainly an advancement in shaft fitting because golfers had a much better idea of the type of shaft flex in their shafts and how it will perform for them. The problem was that other characteristics of the Rifle Shafts may not be well suited or liked by many golfers.

Eventually, the QC of shaft companies did greatly improve. In fact, Aldila now measures the frequency of some of their shafts and gives that CPM (cycles per minute) on their Web site.

Also, many clubfitters are frequency matching shafts themselves. However, I do believe some of these clubfitters are a little less than forthcoming on how they do this. What these clubfitters do is they trim the tip end and the butt end of the shaft until they get the club to the length you want and the frequency you want.

In order to do this, they use a parallel tip shaft because you really cannot tip trim a taper tip shaft.

Taper Tip shafts are 0.355 inches in diameter. They of course fit into Taper Tip clubhead hosels. Most OEM’s have taper tip hosels in their clubheads. Parallel tip shafts have 0.370 inch tip diameter. You can trim Parallel tip shafts from both the tip end and butt end of the shaft.

So, how do these clubfitters get the Parallel Tip (.370) shafts into a Taper Tip hosel (.355)? They simply use a drill into the clubhead and make the hosel .370 inches in diameter.

While that sounds simple, many golfers do not like Parallel Tip shafts for various reasons like the bigger tip generally making the shafts feel stiffer. I personally use parallel tip shafts in my own Wishon irons and I’m quite happy with them. However, if you get into the frequency matching game by using parallel tip shafts and trimming from the tip and butt end in order to get the frequency right…now you run the risk of dramatically changing the characteristics of the shaft.

The way most parallel tip shafts work is you’ll have specific trimming instructions. For instance, they’ll tell the user to trim 1-inch off the tip of the shaft and then trim the butt end to the length you want the club for your 5-iron. Then with your 9-iron the instructions say trim 2-1/4 inches off the tip and then trim the butt end to length.

However, if you are trying to use parallel tip shafts to frequency match, you may wind up trimming much more off the tip or the butt end. The more you trim off the tip…the lower the kick point of the shaft will be and that will make the ball fly higher and spin more. More from the butt end, the kick point of the shaft is higher which can make the ball fly lower with less spin. All of this can affect Swingweight and if you’re into MOI Matching…greatly affect the MOI as well.


WISHON ON SHAFTS



Recently, Tom Wishon made an interesting post titled ’10 Myths About Shafts.’ I would highly recommend reading it. Here’s the link: http://www.golfwrx.com/forums/topic/552963-10-myths-about-shafts/

Wishon discusses ‘shaft bend profile’ and its importance. As Wishon states, the SAME shaft equipment manufacturer can have different shaft models labeled the same flex, but the way those shafts perform and feel can be drastically different.

What a shaft bend profile does is it measures the shaft frequency throughout the entire shaft as the butt section of the shaft will have a higher frequency than the tip section. Here’s a sample chart showing a shaft and it’s frequency from the tip end (left side of the chart) to the butt end of the shaft (right side of the chart).



Here’s a Shaft Bend Profile chart showing 3 different shafts from Diamana.

DIAMANA SHAFT BEND PROFILE CHART

I think golfers (and clubfitters) can use these shaft bend profiles to their advantage in a couple of ways:

1. If you really love a very expensive golf shaft, you can start searching for a cheaper alternative that has the same bend profile. As Wishon says, he has yet to find a $300 shaft that cannot be ‘duplicated’ at a much lower price.

2. If you’re not quite in love with a shaft, you can search for shafts that have bend profiles more to what you are looking for. Let’s say you like the feel and the trajectory of a shaft, but want something with a lower spin…you may want to look for shafts that have the same bend profile, except with a stiffer tip section.

And that’s what Wishon’s Shaft Bend Profile Software is about. It has the shaft bend profiles of most of the major shaft manufacturer’s shaft models, so I can use that to compare shaft bend profiles and do a better job of reaching one of my 2012 Goals…doing a better job of having a driver that fits my swing.

As I mentioned with MOI fitting and matching, I *can* hit some great shots with a shaft that is too flexible for my swing. The problem is timing when the club kicks. I believe with MOI fitting, the weight suits the golfer’s swing and they don’t have to worry nearly as much about the shaft not kicking at the right time. And with understanding shaft bend profiles, one can stay away from shafts that don’t come close to fitting them and be able to better fine tune what type of shaft they are looking for.








3JACK