Facts about shafts — What they do
by Tom Wishon
There is no question the shaft is the least understood of all the components of a golf club. The first reason is because most golfers simply do not know what the shaft can and cannot do to influence the outcome of a shot. Second, many golfers think that the shaft does what it does for every golfer who uses that shaft. It is very common for a golfer to switch shafts, see a visible change in ball flight, and attribute all of the shot change they see to the shaft. In reality, there are other fitting parameters in the club that underwent a significant change when the new shaft was installed, which may or may not be the reason for the change in ball flight.
In parts 1 and 2 of my series on shafts, you have learned how it is possible to measure and express a shaft’s flex and bend profile design in quantitative terms. The graphs and stiffness measurement data take flex and bend profile comparison and selection to the same level of quantitative measurement as all the other specs of the golf club which are measured in degrees, grams and inches.
This is Part 3 in a series of technical articles about shafts by Tom Wishon. He wrote a 3 part series to educate golfers about shafts…
But in the end, even with the ability to empirically compare shaft flex and bend profile, there are still questions:
How does the shaft contribute to ball flight?
For who does it contribute?
How much does it contribute?
How does it actually contribute?
I’ve spent decades in my career doing this study and I strongly believe that we do know the answers to these often confusing questions about the performance of the shaft.
The Shaft Can Have an Effect on launch Angle, trajectory and spin rate. How much of an effect the shaft has on these shot parameters depends on the lateness of a golfer’s release, their clubhead speed and how aggressive their downswing tempo is. In addition, how much the shaft can change launch angle, trajectory and spin for golfers who do have the swing characteristics to make the shaft perform depends completely on the overall stiffness and bend profile of the new shaft versus the golfer’s previous shaft.
For those of you who have read some of my articles and posts on shafts, you have heard this part before. The shaft’s effect on launch angle, trajectory and backspin only become visible as the golfer’s release occurs later and later in the downswing. In addition, the shaft’s effect on trajectory and spin progresses more and more as the golfer’s clubhead speed and downswing aggressiveness/force increases.
Golfers who unhinge the wrist cock early to midway in the downswing do NOT experience a difference in launch angle, trajectory or backspin from shafts of different flex and different bend profile. They do experience a difference in how solid or boardy the impact with the ball is. But as the release gets to midway on the downswing, and progressively a little later and later beyond midway in the downswing, the shaft begins to have a little more and more effect on launch angle, trajectory and spin.
The reason the shaft can have an effect on launch angle, trajectory and spin for later release players is because of the way the timing of the bending of the shaft can affect the dynamic loft of the clubhead at impact. When the golfer begins to unhinge their wrist cock angle on the downswing, the golfer’s hands/arms begin to slow down while the club accelerates.
Yes, for EVERY golfer, once he or she unhinges the wrist cock angle, their arms slow down. Because the hands are holding the club while the arms are slowing down, the acceleration of the club begins to push the shaft against the resistance of the slowing arms/hands into a forward bend position.
The later the golfer’s release, the more the forward bending of the shaft can arrive at impact in that forward bend position. For a midway release, the shaft only has a slight amount of forward bend by the time the clubhead gets to the ball. For an early to midway release, the forward bending of the shaft happens too soon, so that by the time the clubhead gets to the ball, the shaft has rebounded back to straight, thus not changing the dynamic loft of the clubhead at impact.
It is important to understand that two golfers can have the same launch angle but have totally different trajectories and backspin amounts from each other. If two golfers with different clubhead speeds have the same swing path, same angle of attack and same hand position at impact, the launch angle will be the same but the trajectory and spin rates will differ. The higher the clubhead speed of the golfer, the higher the trajectory and spin will be for any given launch angle.
How much can the shaft affect the launch angle and spin rate for those golfers who do have a later to very late release?
Two things control this. First, when a golfer uses a different shaft than he has been playing, the only way the shaft can change the launch angle and spin is if the new shaft is different in its overall stiffness design than the old shaft. Second, how much the shaft can affect launch angle and spin also depends on how flexible or stiff the shaft is in relation to the golfer’s clubhead speed, transition and tempo force and point of release.
First, I see TONS of posts and questions in the GolfWRX forums that say something like:
“I need a recommendation for a good low-launching (or high-launching), low-spin shaft.”
Such a question is asked as if the golfer thinks that a shaft will demonstrate the same effect on launch angle and spin for every golfer who uses it.
While the shaft companies like to say their shafts are designed to have certain launch and spin characteristics, the truth is that a shaft can only offer a low or higher launch/spin if it is stiffer or more flexible THAN WHAT THE GOLFER USED BEFORE.
In other words, what is a low-launch and low-spin shaft for golfer A can be a high-launch and high-spin shaft for golfer B, and vice versa. FOR THE SAME SHAFT, the golfer with the higher clubhead speed, later release and more upward angle of attack is going to hit shots with a higher launch, higher trajectory and higher spin than will the golfer with a lower clubhead speed, earlier release and more downward angle of attack.
So, for golfers who are looking for a low-launch, low-spinning shaft, the only way you can find that is to:
Know precisely what the overall stiffness and bend profile stiffness design is of the shaft you now play, and
Know the overall stiffness and bend profile stiffness design of all other shafts so you can pick one that is stiffer overall and/or has a more stiff tip section design.
Shafts are dumb animals. They only do what their owner’s swing forces them to do.
Second, if a late release golfer were to play with a soft L one day and a stiff X the next, without question the difference in launch angle, trajectory and spin would be very significant. But common sense says this isn’t going to happen because each golfer should play a shaft that has its overall stiffness and bend profile properly matched to the golfer’s unique combination of clubhead speed, transition/tempo force and point of wrist cock release.
Sure, some of us prefer to play a shaft that feels stiffer. Some of us like to play a shaft that feels a little more flexible. If a golfer has a preferred sense of bending feel for a shaft, without question, regardless of their clubhead speed, transition/tempo and point of release, their best shaft has to satisfy that bending feel preference or their swing tempo/timing/rhythm/release gets screwed up and becomes inconsistent.
But within shafts that reasonably fit a golfer’s clubhead speed, transition/tempo and point of release, typically the maximum difference seen in launch angle from different shaft options is in the area of 2.5 to 3 degrees. As far as spin difference, that depends on the clubhead speed of the golfer. A shaft that launches the ball 2 degrees higher for a golfer with an 80 mph clubhead speed would typically increase spin by 350 to 400 rpms, while a shaft that launches the ball 2 degrees higher for a golfer with a 100 mph clubhead speed would typically increase spin by 500 to 600 rpms – that is, of course, given the same clubhead and same other assembly specs of the club.
So the bottom line is this – shafts can bring about changes in launch angle, trajectory and spin, but only for golfers with a later to late release, and only to the extent that their overall stiffness and bend profile are different from the shaft the golfer previously played.
If the golfer has developed a preferred sense of bending feel for the shaft, playing a shaft that satisfies that preferred bending feel will enable the golfer to achieve their highest clubhead speed. However, for such a golfer, playing a shaft that does NOT perfectly match their preferred bending feel will bring about a lower clubhead speed, worse accuracy and more off-center hits.
Here’s a statement about shafts that I have heard a few times in my career:
“Different shaft designs can be designed with a higher tip velocity to allow the golfer to achieve a higher clubhead speed.”
That’s not correct. As I said before, shafts are dumb animals. They ONLY do what the swing characteristics of their owners cause them to do. Whenever a golfer uses a shaft that has its weight, overall stiffness and bend profile well matched to the golfer’s clubhead speed, transition/tempo, point of release AND preference for bending feel, that’s when the golfer will achieve their highest clubhead speed. But this is only if the specs of length, loft, face angle, total weight, swing weight, and grip size are correctly fit to the golfer as well.
Give that same shaft to a different golfer with the same clubhead speed but a different combination of transition/tempo, point of release and preference for bending feel and that same shaft will result in a lower clubhead speed with far worse performance for that golfer BECAUSE THE SHAFT DOES NOT FIT THE SWING CHARACTERISTICS OF THE OTHER GOLFER.
A shaft can only exhibit a high level of “tip velocity” for the golfers whose clubhead speed, transition/tempo, point of release AND preference for bending feel is perfectly matched to the weight, overall stiffness and bend profile of the shaft.