Thursday, October 24, 2013

How Should a Golfer Select the Right Shaft for His/Her Swing?


One of the most common posts I see is when one golfer asks other golfers for a shaft recommendation. These posts seldom say anything about a golfer’s swing characteristics other than his or her handicap and sometimes a clubhead speed. Invariably, many different shaft recommendations follow, rarely a follow up question to ask the golfer anything more about his or her particular swing characteristics.

Shafts do not perform the same way for all golfers. Shafts perform differently for different swing characteristics because different swing characteristics make shafts bend and twist differently. Most golfers are aware that their clubhead speed has relevance to what shaft they should play. But in addition to the clubhead speed, there are several other swing characteristics which determine how different shafts can and do perform differently for different golfers.

Shafts are in essence, “dumb animals.”  There is absolutely NO magic to the performance of a shaft – they ONLY do what their owner’s swing characteristics ordain them to do. For some golfers, there is some additional performance contribution from the center of gravity location inside the clubhead. However, there are a lot of different variations in how golfers swing the club with respect to the specific swing characteristics that dictate how a shaft will perform.  The whole idea of analyzing the swing characteristics which are pertinent to shaft performance is to allow me to have a way to systematically ELIMINATE shafts from consideration for a golfer, so what is left would be a smaller, manageable number of shafts with which each golfer could play.

The KEY elements of the golf swing in shaft fitting are:

1.      Clubhead Speed

The clubhead speed affords a basic, rudimentary, BEGINNING indication for the approximate overall amount of bending force a golfer may put on a shaft. However, it is very common for two golfers with the same clubhead speed to put totally different amounts of bending force on a shaft.  It is also common for two golfers who put the same bending force on a shaft to have different clubhead speeds. This is why a good shaft fitter has to analyze other characteristics of the golf swing to get more of an idea of how much bending force the golfer is putting on the shaft for his/her swing speed, when that bending force is being applied to the shaft and where on the shaft is the most bending force being applied.  Clubhead speed gives us a starting point to help us begin to narrow the choice of possible shafts for a golfer in the fitting process. But it only tells us a part of the story.

 2.      Downswing Transition Force

The force with which the golfer starts the downswing determines the initial bending force on the shaft. In other words, how much the shaft is initially “loaded” is chiefly determined by the golfer’s transition force to start the downswing. Of two golfers with the same clubhead speed, the one with the stronger, more forceful transition will need a stiffer shaft (a shaft with a swing speed rating that is higher than the golfer’s swing speed). Of two golfers with the same clubhead speed, the one with the smoother, passive transition will need a more flexible shaft (a shaft with a lower clubhead speed rating than the golfer’s swing speed).

In addition, a golfer with a stronger transition typically is better fit into a HEAVIER weight shaft. A strong/forceful transition with a very light shaft can result in a swing tempo that gets too fast and too inconsistent, although it can be possible to use a higher than normal swingweight to allow a golfer with a strong transition to not get too quick when using a very light shaft.

3.      Downswing Tempo/Downswing Aggressiveness

I said the transition force determines the INITIAL loading of the shaft.  The downswing tempo determines how much that initial loading may change during the rest of the downswing before impact.  Tests have been performed with special sensors on the shaft reveal that it is extremely rare for a golfer to increase the loading of the shaft during the downswing. It is not very common for a golfer to maintain the same load on the shaft during the downswing, either. Almost every golfer loads the shaft the most at the beginning of the downswing, after which the loading on the shaft begins to decrease from the moment the transition turns into the downswing.

A good shaft fitter will analyze the downswing tempo to estimate if the golfer is maintaining their initial loading of the shaft, slightly losing some of the loading or substantially losing it. In more recent research, I have come to the belief that the transition and tempo blend together in terms of the golfer’s ability to put a bending force on the shaft and maintain it or not to the point of release. Hence the good shaft fitter will analyze the transition/tempo together in one overall observation to decide whether the golfer is an AGGRESSIVE HITTER, a SMOOTH SWINGER, somewhere in between or variations of each extreme.  It really is not necessary to split the hair too fine on this evaluation. Good fitters chiefly think in terms of HITTER, SWINGER or AVERAGE when it comes to evaluating the effect of the transition/tempo on the golfer’s ability to load the shaft.

How is the analysis of the golfer’s transition/tempo used to help narrow down the shaft recommendation? 

The more forceful and aggressive the golfer’s transition/tempo, the more the shaft would be selected to have a swing speed rating that is a little higher than the actual swing speed of the golfer. Vice versa, the more passive, smooth and easy the golfer’s transition/tempo, the more the shaft would be selected to have a swing speed rating that is a little lower than the actual swing speed of the golfer.

For example, let’s say we have three golfers, each with a 100 mph clubhead speed.  Golfer No. 1 has a short, three-quarter length backswing with a fast, forceful transition and an aggressive downswing. Golfer No. 2 has a normal backswing length with some sense of transition force and downswing aggressiveness but not nearly as much as Golfer No. 1. Golfer No. 3 has a smooth, rhythmic, almost passive transition and tempo that identifies him as far more of a “swinger” than a “hitter.”

For basic fitting, Golfer No. 2 would be advised to look among shafts that have a 95-105 mph swing speed rating because his swing characteristics are putting an average amount of bending force on the shaft for his 100 mph clubhead speed.

Golfer No. 1 (strong/forceful transition and tempo) would be advised to look among shafts that would have a 100-110mph swing speed rating because his swing characteristics are “loading” the shaft more from him putting an ABOVE average amount of bending force on the shaft for his 100 mph clubhead speed. And Golfer No. 3 (smooth, passive transition and tempo) should choose from shafts that have a 90-100mph swing speed rating because his swing characteristics are “loading” the shaft much less for his speed and put a BELOW average amount of bending force on the shaft for his 100mph clubhead speed.

In short, as the golfer puts more bending force on the shaft due to his Transition and Tempo, the swing speed rating of the shaft needs to increase higher than the golfer’s actual clubhead speed. And as the golfer puts less bending force on the shaft due to his Transition and Tempo, the swing speed rating of the shaft needs to decrease lower than the golfer’s actual clubhead speed.

But what’s next after finding the shafts which have a swing speed rating that corresponds to the golfer’s clubhead speed and adjustments for the golfer’s transition and tempo?

4.      Point of Wrist-Cock Release During the Downswing

The key swing characteristic which good shaft fitters analyze to determine the correct TIP STIFFNESS design of the shaft for the golfer is the point the golfer unhinges their wrist cock release on the downswing. In swing mechanics terms, the action of unhinging the wrist cock angle is called the RELEASE.

The point when the golfer releases the club is what determines WHEN the shaft goes from being “loaded” to being “unloaded.”  The point when the golfer releases the club determines when the shaft moves from a “flexed back” position into a “flexed forward” position.  The point of release also determines when the clubhead achieves its highest speed.

Once the golfer unhinges the wrist cock angle, the arms immediately begin to slow down while the clubhead speeds up. If the golfer releases the club too early, the clubhead reaches its highest speed well before it gets to the ball. With an early release, by the time the clubhead gets to the ball, the clubhead speed has slowed down. This slowing down of the clubhead before impact even happens for golfers who release the club midway on the downswing – though not as much as with an early release.

The only golfers who achieve their highest clubhead speed right when the clubhead meets the ball are golfers with a late release.  Hence this is another reason why a late release is such an important swing skill for golfers to achieve to be able to play to the best of their physical skills.

In shaft fitting terms, the later the golfer releases the club, the more tip stiff the shaft COULD be. And conversely, the earlier the golfer releases the club, the more tip flexible the shaft should be.  Because the actual point of release can vary all the way from the start of the downswing to the very end, so too the tip stiffness design of the shaft is chosen to correspond.  Early release = most tip flexible; Latest release = most tip stiff;  Release in between early and very late = tip stiffness in between.

You can now start to see why we need to have quantitative stiffness measurements of shafts so we can choose the right level of stiffness for golfers with varying levels of transition/tempo force and different points of release. With only letters for flex and generic terms for tip stiffness or bend point, shaft fitting is little more than a trial-and-error guess.

5.     The Qualitative Side of Shaft Fitting — The Golfer’s Perception and Preference for the Shaft’s BENDING FEEL

Talk about something that can throw a monkey wrench into all the logical things that we have taught so far about shaft flex/bend profile fitting!  If you want to know why some golfers play well with shafts which are “on paper” considered to be too stiff, too flexible, too tip stiff or too tip flexible for their clubhead speed, transition/tempo and point of release, this is the reason why.

If a golfer has developed a specific preference for a type of bending feel of the shaft during any point in the swing, that feel preference has to be THE GUIDING FACTOR in the shaft fitting process. During the fitting process, the smart, experienced clubfitter knows to interview the player and ask questions to assess the golfer’s level of perception for the bending feel of the shaft and whether they have acquired specific “likes and dislikes” for various aspects of the shaft’s bending feel during the swing.

The very best way to incorporate a golfer’s preference for shaft feel in the shaft fitting process is to have the golfer reveal specific shafts they have either liked or disliked in previous or current clubs. If these shaft models/flexes are searched in the Bend Profile Software we created, the stiffness measurements of those shafts can then be referenced against possible future shaft recommendations to determine if the new shaft selection may or may not satisfy the golfer’s shaft feel preferences.

One of the myths about shaft flex/bend profile performance is when someone states that this or that shaft is designed in a way that can actually increase the bending velocity of the shaft to offer a golfer a higher clubhead speed.  This is impossible because of the physics of tube design and performance.  However, it is very possible for a golfer to change to a different shaft flex/bend profile design and experience a measurable increase in clubhead speed.

How this happens is how the new shaft falls into the golfer’s preference for the bending feel of the shaft. Give a golfer a shaft that feels perfect in terms of how much it bends, when it bends and where it bends in relation to the golfer’s acquired preference for bending feel and that golfer will achieve his most free, most unrestricted and most fluid release through the ball.  And it is from this – having a shaft that feels perfect in every way to the golfer – that they are able to achieve a higher clubhead speed.

On the other hand, put the golfer into a shaft that demonstrates a feeling of being too stiff or too flexible in some way compared to the golfer’s preference for bending feel and they most typically will begin to change their swing to make the shaft perform and feel as they prefer.  Manipulating the swing means a lack of free motion, free unrestricted release and a lower clubhead speed with less swing consistency.

Again, to not have a truly quantitative way to analyze shafts, trying to turn a golfer’s feel preferences for the shaft into a valid new shaft recommendation becomes a trial and error process.

6. Putting It All Together

The higher the golfer’s clubhead speed, the more forceful/aggressive the transition and tempo, the later the release, the more the flex and the bend profile of the shaft become a contributor to the launch angle, trajectory and spin rate for the shot.   The lower the clubhead speed, the more passive the transition and tempo, the earlier the release, the less important the shaft’s flex and bend profile are to performance. But for ALL golfers, the WEIGHT of the shaft is an important part of the shaft selection process.

The higher the golfer’s clubhead speed, the more forceful/aggressive the transition and tempo, and the later the release IN RELATION TO THE SWING SPEED RATING and TIP STIFFNESS OF THE SHAFT, the more the shaft can increase launch angle, trajectory and spin.

The shaft only just begins to contribute to launch angle, trajectory and spin in a gradual increasing manner as the golfer has a midway to later to very late release. Midway release, the flex and bend profile begin to matter a little. Very late release, the stiffness design of the shaft matters a lot more. For golfers with an early to before midway release, the flex and bend profile of the shaft do virtually nothing to the launch angle, trajectory and spin of the shot.   The shaft’s WEIGHT becomes the only key shaft fitting factor for golfers with an early to before midway release.

The ONLY ways the shaft can lower launch angle, trajectory and spin is:

i.     if the shaft is either more stiff overall than the golfer’s previous/current shaft, OR,

ii.     if the tip section of the shaft is more stiff than the tip section in the golfer’s previous/current shaft.

Just because a shaft is said to be tip stiff will not reveal whether it is a lower spin shaft than what you play now. A shaft has to be more stiff overall and/or more tip stiff than what you play now to have any effect on lowering launch angle, trajectory and spin.

The golfer’s preferences for a specific bending feel of the shaft overshadow the stiffness and bend profile fitting analysis compiled from the clubhead speed, transition/tempo and point of release.  In all cases for all golfers, you do go through the stiffness and bend profile fitting analysis compiled from the clubhead speed, transition/tempo and point of release, but you listen hard and consider modifying the recommendation when the golfer says they have a specific preference for the bending feel of a shaft.

 

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