Shaft profile and effects

[dschultz6072]

I haven't bought the AS2 video, but I was wondering if there was any new discovery of the effects of using a club shaft that isn't fit to the individual. I've asked many people, but their feels are all subjective. Some say stiff leaves high right, some say weak leaves high right, etc. Does it all depend on the style of swing?

 

[Frans@France]

... I've asked many people, but their feels are all subjective. Some say stiff leaves high right, some say weak leaves high right, etc.

They are all correct, it depends on that person sensitivity for the club. You could however also start reading this :
The Effect of Differing Shaft Dynamics on the Biomechanics of the Golf Swing

and after reading question why the researcher needed to throw out the first few shots to get consistant data and question why the researcher allowed the golfer to see the ball flight

It is a fantastic research project with a lot of attention for details, just such a shame they did throw out that data and allowed feedback by ballflight.

 

[magicmarker]

Several researchers have investigated the possibility that the golf shaft behaves
like a spring in a spring-mass system; in other words, the shaft stores energy
during the first part of the downswing and releases it just before impact. The
extra velocity that this unloading may add to overall club head velocity has been
termed „kick velocity‟ and “is defined as the derivative of lead/lag deflection with
respect to time” (MacKenzie, 2005, p. 89). Based on the spring-mass system
analogy, the oscillating shaft should be on its way from a bent backwards
position to a bent forward position and be straight at impact. At this point, strain
energy would be at its minimum and kinetic energy at its maximum, thus adding
the maximum „kick velocity‟ component to the overall club head velocity: “The
optimum condition is where the shaft is straight at impact so that kinetic energy
is maximised and stored potential energy is minimized” (Butler & Winfield, 1994,
p. 261).

In far less words, this is exactly what I picture in my mind when I think about 'going normal'. Thanks for sharing Frans, great article.

 

[Todd Dugan]

I haven't bought the AS2 video, but I was wondering if there was any new discovery of the effects of using a club shaft that isn't fit to the individual. I've asked many people, but their feels are all subjective. Some say stiff leaves high right, some say weak leaves high right, etc. Does it all depend on the style of swing?

Well, there's "subjective opinion", and then there's scientific fact. So if a "controlled" robot (no placebos, please) swung with a more flexible shaft, the ball would fly higher and more left, and visca versca. This is because as the shaft is flexed more tip-forward, loft is added and the clubface closes more.

Hard to beat Tom Wishon's "Search For The Perfect Golf Club" for the facts on how golf clubs work.

 

[SteveT]

If you're searching for a suitable shaft for your swing you must determine your unique downswing shaft loading style.

Here are three graphs of typical downswing shaft loading profiles as determined from TrueTemper ShaftLab testing.

The scientific study backing up these curves is in Science and Golf II (1994): The Dynamic Performance of the Golf Shaft During the Downswing - J.H. Butler and D.C. Winfield (both of TrueTemper)

You should use the most flexible shaft possible for your swing speed and shaft loading, otherwise you will be shoveling instead of "whipsnapping" the clubhead.

 

[cwdlaw223]

I've used the ShaftLab many times and it recommends for me (and almost everyone else I know who's been on it) into a regular shaft. Why a regular? Because, IMO, the software is built to maximize loading of the shaft without regard for other variables such as lead deflection. Maybe I'm not using the extra load properly? Don't care. I use equipment to adjust to me, not the other way around.

R = left city for me and worse launch conditions.

I play X flex shafts.

Tom Wishon has great stuff!

 

[SteveT]

I've used the ShaftLab many times ........

R = left city for me and worse launch conditions.

I play X flex shafts.

What shaft loading profile did you get from the TT ShaftLab... and were the loadings the same for the driver and 5-iron?

Apparently you can have a hybrid profile combining two of the loadings.

 

[dschultz6072]

Well, there's "subjective opinion", and then there's scientific fact. So if a "controlled" robot (no placebos, please) swung with a more flexible shaft, the ball would fly higher and more left, and visca versca. This is because as the shaft is flexed more tip-forward, loft is added and the clubface closes more.

Hard to beat Tom Wishon's "Search For The Perfect Golf Club" for the facts on how golf clubs work.

Nice. So my left miss when I go at it isn't entirely all in my head. I have to dial back so much with my hybrids to get them to go straight. They're still from my first set of clubs and R-flex.

 

[cwdlaw223]

What shaft loading profile did you get from the TT ShaftLab... and were the loadings the same for the driver and 5-iron?

Apparently you can have a hybrid profile combining two of the loadings.

I have the sheets somewhere. Never had a combination and I think it was for iron shafts only. The guys at Izett Golf in Ardmore, PA might still use it. That's where i had it done couple times. I spoke with numerous people who were scratch or better that went through the system and we all had R flex recommendations. The Mizuno shaft optimizer is very good. The devil is in the programming and the assumptions behind the programming.

 

[birly-shirly]

Hmm - so the paper that Frans posted had this to say in the abstract

"The face angle (p = 0.176) and the ball‟s impact
location (p = 0.907 and p = 0.774) were unaffected by changes in shaft
stiffness. Decreases in shaft stiffness were associated with significantly more
shaft bending at the transition from backswing to downswing (p < 0.001), but the
amount of lead bending at impact was found to be largely unaffected by shaft
stiffness. The test protocol from the follow-up study was repeated using a golf
robot, confirming the results for ball speed and wrist kinematics if the impact
speed was set to replicate the mean club head speed achieved by the human
players. Results from this thesis contradict the conventional view that reducing
shaft stiffness leads to an increase in lead bending at impact and, consequently,
to an increase in ball launch angle. Overall, these results suggest that it is
unlikely that changes in overall shaft stiffness in themselves have a marked
effect on driving performance."

For sure, you can debate the methodology used - but bear in mind the author now has a phd in his subject, he was professionally supervised in undertaking his research, and he has no vested interest in trying to sell you new shafts, clubs or fitting services...

 

[SteveT]

Dr. Betzler's PhD thesis is very informative and I recommend all serious golfers/teachers read and study it. It will help you relate your golfswing "feel" to scientific "fact".

The "References" section is very revealing; with more and more scientific studies examining the golfswing and equipment. There is a spin-off effect to all these scientific studies with new equipment designs and testing equipment such as TM and FS.

However, the teaching methods still lag behind the physical science and psychological sciences, suggesting that the teaching of the golfswing must be significantly upgraded if golf performance is to improve.

 

[mjstrong]

So we have one study that states the shaft stiffness doesn't affect club head speed (article in the Journal of Applied Golf Research recently), but does affect the Face's horizontal and vertical components at impact...and, on the contrary, this study states that delivered Face angles are unaffected.

Perhaps the stiffness of a shaft has relatively little to do with performance, and it's the other factors (weight, torque, etc.) that come into play much more. It could also be that, there are simply too many variables to accurately profile the effects of shafts on players in a nice, neat manner.

 

[OLIVER1]

What a great thread.
What effect, if any, will the new way of looking at the transition have on shaft loading?

 

[SteveT]

So we have one study that states the shaft stiffness doesn't affect club head speed (article in the Journal of Applied Golf Research recently), but does affect the Face's horizontal and vertical components at impact...and, on the contrary, this study states that delivered Face angles are unaffected.

Perhaps the stiffness of a shaft has relatively little to do with performance, and it's the other factors (weight, torque, etc.) that come into play much more. It could also be that, there are simply too many variables to accurately profile the effects of shafts on players in a nice, neat manner.

Please examine the TT ShaftLab downswing shaft loading profiles posted on this topic thread and decide if there are different "feel" loadings.

Many call themselves "feel" golfers but few are willing to quantify their "feel" sensations into something even semi-objective. Is it because "feel" is something intimate and special, and not to be questioned?

 

[drewyallop]

This is what I heard at ASII: Try a bunch of different shafts and choose the one that allows you to achieve the best timed release. Comments?

 

[drewyallop]

Several researchers have investigated the possibility that the golf shaft behaves
like a spring in a spring-mass system; in other words, the shaft stores energy
during the first part of the downswing and releases it just before impact. The
extra velocity that this unloading may add to overall club head velocity has been
termed „kick velocity‟ and “is defined as the derivative of lead/lag deflection with
respect to time” (MacKenzie, 2005, p. 89). Based on the spring-mass system
analogy, the oscillating shaft should be on its way from a bent backwards
position to a bent forward position and be straight at impact. At this point, strain
energy would be at its minimum and kinetic energy at its maximum, thus adding
the maximum „kick velocity‟ component to the overall club head velocity: “The
optimum condition is where the shaft is straight at impact so that kinetic energy
is maximised and stored potential energy is minimized” (Butler & Winfield, 1994,
p. 261).

In far less words, this is exactly what I picture in my mind when I think about 'going normal'. Thanks for sharing Frans, great article.

This from MacKenzies presentation at ASII (segment 1, about 1:35): The clubhead kicking forward into impact does not increase club head velocity because the release of shaft torque that causes the kick simultaneously slows down the hands.

And related: a change in shaft stiffness will not increase clubhead velocity significantly (this confirmed by Woods' tests at Ping). But changing stiffness will change the amount the club is dynamically lofted and dynamically closed.

Another interesting point from Woods: if a shaft is well made to begin with there is no need for "puring" or "spining".

Has anyone here bought the ASII video?

 

[mgranato]

So we have one study that states the shaft stiffness doesn't affect club head speed (article in the Journal of Applied Golf Research recently), but does affect the Face's horizontal and vertical components at impact...and, on the contrary, this study states that delivered Face angles are unaffected.

Perhaps the stiffness of a shaft has relatively little to do with performance, and it's the other factors (weight, torque, etc.) that come into play much more. It could also be that, there are simply too many variables to accurately profile the effects of shafts on players in a nice, neat manner.

This

 

[birly-shirly]

Which?

 

[Jim Kobylinski]

Listen, i am no scientist and am not going to go against what these scientists have discovered, how ever there is the "human" element. I've done a lot of fittings over the years and humans will do allllllllllllll kinds of things to their swings to make "a shaft" work. This can affect speed and face angle.

It's a bit like chicken or the egg but none of the less it happens.

 

[sharkey35]

Another perspective you might find enlightening:

10 Myths About Shafts - GolfWRX