came across this and figured you and Scoot could gain a "bit" of insight
from Tom Wishon
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There is no question the shaft remains one of the most confusing, if not THE most confusing part of the golf club. I'm not here to sell anything, in fact I never have and never will because I only want to offer facts and information that will erase the myths so golfers can end up spending their money for what best for THEIR game and swing. Many of you have known me for years. During that time, I like to think that you have NEVER heard me offer any information other than simply to tell the truth as I know it when it comes to the performance of any part of the golf club or its whole. I don't plan to change that because I know how hard it is and has been for golfers to get straight and truthful answers to their questions about golf clubs.
I have spent a huge amount of time in my career digging into the function, performance and design of shafts. I've had a lot of help along the way from some of the best minds in shaft R&D - Robin Arthur (ex Grafalloy/Royal Precision VP Engineering), John Oldenburg (current Aldila VP Engr) and Graham Horwood (ex Apollo and current TTemper VP Engr), as well as some very smart mech engrs I have used to bounce data off, when I could not come up with the conclusions or answers myself. What I am about to offer you with regard to the shaft's performance and function is not tainted or tilted in anyway - it is simply the facts as we, meaning me and the top brains in shaft design/engineering in the industry, believe the shaft performs and functions for different golfers.
This is going to be a little long - I apologize in advance - so if you're not interested in learning what those of us who REALLY take it seriously to figure these things out know as substantiated by facts and hard data and real science, click away from this and head to another post/thread.
The main reason shaft performance is so confusing is because the same shaft reacts totally different in how it bends and twists to different movements of the golf swing. Since we golfers do not all swing the club in the same way, the same shaft can perform one way for one golfer, and totally different for another.
That's not the way it is with the clubhead. Sure, two golfers with totally different swings can hit the same clubhead so it generates a different distance, different launch angle, different spin and all that. But it is a fact that if you take the same clubhead and change its loft, or face angle for example, the TYPE OF CHANGE in the ball flight will be the same for all golfers. Say you hit a 10* driver with 0 face angle low and straight, while I hit it higher and with a fade - that certainly can happen because your swing delivers that 10* loft with less DYNAMIC LOFT and with a square face to the ball at impact, while my swing delivers that 10* loft with MORE DYNAMIC LOFT and with an open face. OK, lets say we both change to hit a different head with 12* loft and a 2 hook face angle. Your swing will hit the ball a little higher and a little to the left - I'll hit it higher than I did before too and I will hit it with less of a fade or maybe even straight. What I am saying is the ACTUAL FLIGHT may be different but the RELATIVE CHANGES from the spec differences in the two different heads will still be the same for me and you - all other things being equal.
It's not that way with shafts because they are SO DEPENDENT on various, specific swing moves to bend and twist in different ways.
Regardless what material a shaft is made from or how it is manufactured, from a performance standpoint, all shafts can be boiled down to be compared by weight, torsional stiffness (torque), length, weight distribution (balance point) and the distribution of stiffness over their length (bend profile). Flex as we refer to it by letter codes is all tied up within the bend profile, which of course can be varied in a ton of different ways.
That's it - those are the only things that make one shaft PERFORM differently than any other. Now if you want to talk FEEL, there are some other things related to the shaft's material make up that will add to these other 5 factors that can affect FEEL. But we're not talking feel here now, we're talking about performance. Feel is very tough to quantify chiefly because different golfers perceive, note, detect, relate to the feel of the shaft in the shot differently in large part because of differences in their neurological make up and/or their inherent athletic/swing ability.
Take this one to the bank first - forgetting the feel aspect for now as I asked so we can talk only of performance, if three shafts have the same weight, torque, length, bal pt and bend profile, it does not matter if one is made from sheet wrapped, super high dollar composite material, the next from filament wound low dollar material, and the third from steel - they will PERFORM the same for the same golf swing moves. They may and will likely FEEL different to different golfers, but again, we're talking about PERFORMANCE HERE. This is no myth, this is simply a product of the science of what makes a shaft perform the same or differently and this is a fact that the top shaft minds on this planet agree with.
As to what the shaft does for any shot, first of all, the shaft is NOT the engine of the club. In a "car analogy" it is more like the TRANSMISSION because it delivers the force/energy/work from the golfer to the ball through the clubhead. Many times I have proved this to golfers or clubmakers by building them two clubs to hit - one with the perfect clubhead specs for their swing/manner of play but with a completely wrong shaft, and the other with a perfectly fit shaft mounted to a clubhead with totally wrong specs for how they swing and play. In hitting the two clubs, sure, the one with the totally wrong shaft won;t FEEL as good, but from a PURE PERFORMANCE standpoint, the golfer will hit the ball more consistently solid, farther and straighter with the perfect clubhead/wrong shaft than with the perfect shaft, wrong clubhead. This point is NOT done to make the golfer play with a club that has the right head and wrong shaft - it is only offered as a point to realize that it is the WHOLE GOLF CLUB and all its components and specs that makes it work well or not for any golfer.
Performance wise you have these elements only which are controlled by the shaft -
1. The shaft is THE main contributor to the total weight of the golf club and from that, has a relationship to the swing speed and on center consistency of the shot
2. Partial contribution with the loft/CG of the head to the launch angle of the shot - but only for golfers with a later release of the wrist **** angle and not for golfers with an early release.
3. Partial contribution to the accuracy of the shot from the relationship of the shaft's torque to the downswing force of the golfer - again here is a case where for torque to cause an accuracy problem, it requires a certain type of swing to do that.
The shaft does not SPEED UP the clubhead. The shaft does not work in a BUGGYWHIP action to "slingshot" the ball farther.
But because golfers have hit clubs with different shafts and PERCEIVED that it has done these things, it's now time to bring in that aspect of shaft FEEL.
The better the golfer's swing moves, the more the golfer has played and hit shots and reacted to what they feel, the more the FEEL interacts with the golfer's brain to cause swing changes that may or may not be positive to the shot. How many of you have hit a club where you perceive the shaft to be either too stiff or too flexible so you know to hit the ball decently, you have to make a different swing move of one sort or the other. Shaft feels too stiff and most of us will try to swing harder to make that shaft FEEL and perform like we would like it to feel when we know we hit a great shot. Shaft feels too flexible and most of us try to "slow down" the swing to make the shaft FEEL and perform like we want it to feel.
If the shaft is too light and results in a total weight or swingweight that is not matched well to our swing, again, we have to make swing changes to try to get to that point where we can hit the club ok. Same thing with a shaft that is too heavy. In the end, if we perceive that we ARE making bad swings just to try to make the shaft perform as we want, we dump the shaft and call it a "BAD SHAFT", when in reality it is just the "WRONG SHAFT" for that golfer.
When you've seen a golfer change shafts and end up with a higher swing speed, it is because of what the shaft did to the overall total weight, MOI of the club combined with what it did to the club's overall and total feel and how the golfer reacted to that. Not because the shaft "buggywhipped" more through the ball.
So from a FEEL standpoint, yes, we cannot ignore this with golfers who have a pre-disposition to be able to identify "good shaft feel" and "bad shaft feel" because if we don't address this in the shaft fitting, we are pushing the golfer into making more bad swings as they struggle to make the club feel like they want it to feel when they hit the ball well. Some of these swing changes are very subtle and happen almost sub-consciously, but they are a part of the "cause and effect" of shaft fitting for a lot of golfers. Not all, but a lot.
Yes too to the point that some shafts' specifications are just not well matched to our swing moves and thus PERFORM wrong - the classic example of a shaft that is too flexible somewhere in the shaft for a certain swing type and results in too high of a shot or too much of a "ballooning" high spin shot because of the way the shaft bent forward too much coming into impact and delivered the clubhead to the ball with too much dynamic loft and from that, too much spin. or the shaft that is too stiff somewhere in the shaft and won;t bend forward enough at impact to combine with the loft and CG of the head to generate a high enough launch angle to achieve best distance.
Another thing that makes shaft fitting too much of a trial and error situation and thus contributes to this confusion is that we do not yet have a SIMPLE manner of being able to really convey the possible bending differences of different shaft designs to the many different swing types out there. Yes, we have software now in the industry with which we can look at one form of stiffness measurements over the length of shafts and see a graph of the distribution of stiffness for any shaft. From that we can overlay these graph lines and see that one shaft is stiffer in different parts of the shaft and by how much. But for now that is really only good to be able to identify what the bend profile looks like for a shaft the golfer loves or hates so we can then judge whether a different shaft the golfer may be interested in will be close to or not close to what they like. That's great because if used it can keep a golfer from shelling out money for a shaft they are interested in trying but may not have the same bend profile as one they like now. But for pure, "here's your swing and here's the ONE shaft for that swing" - nope, we don;t have that nailed down perfectly. We can get real close to that based on our knowledge of different bend profile designs in shafts vs what we know about the swing moves that generate more or less bending force on the different parts of the shaft. But it ain't cut and dried completely yet. So we keep 'hunting' and being confused as we do.
What is it in the swing that really changes how the same shaft bends/performs? For now we know these things . . . .
1. The more forceful the start of the downswing (transition) the more the golfer can apply INITIAL BENDING FORCE to the shaft, and in doing this, moreso in the butt to center section of the shaft. We know that if we take a butt flexible design shaft and give it to a golfer who really starts to pour on the coal immediately at the start of the downswing, the result can be more toe hits from too much shaft droop, or at the least a little too flexible of a feel overall to this type of golfer. Likewise if we take a butt firm bend profile design and have the golfer with a real smooth transition, gracual ramp up of the speed of the club on the downswing, this shaft tends to hit the ball a little lower and feels more "harsh" or "boardy" to that type of golfer.
2. The later the golfer is able to hold on to the wrist **** angle on the downswing before unhinging it, the more bending force is put on the tip half of the shaft and the LATER this bending force is put on that part of the shaft. THis is THE KEY MOVE in the golf swing that determines if and by how much, the shaft can combine with the loft/CG of the head to contribute to the launch angle of the shot. Very early release, such as unhinging the wrist **** right when the downswing starts - that move will hit all shafts pretty much the same exact height for the same loft/CG of the head. If there is ever a height difference in clubs with different shafts for the early release golfer, it comes NOT from the bending difference of the shaft, it comes from the total weight, swingweight, length, etc differences that may be in the two clubs and how that affects the golfer's overall swing to possibly result in a more upward or downward angle of attack into the ball - not from the bending. Early release causes the shaft to bend forward TOO EARLY in the downswing - so by the time the club gets to the ball, this forward bending of the shaft from the release of the wrist **** has been DONE AND GONE. Late release means that centripetal force exerted by the unhinging of the wrist-**** angle will act on the CG of the head to "push" it and the shaft with it more forward as the club comes to impact. How much it bends the shaft forward is a product of 1) how late the release, 2) the actual centripetal force exerted in the release (Tiger is about 80lbs, 100mph golfer is about 50lbs, 80mph golfer about 30lbs), 3) the bend profile design of the shaft - ie how stiff and how tip stiff the design, 4) how far back the CG in the head is from the centerline of the shaft.
Real Late release + high centripetal force + very flexible shaft + very deep CG = shaft increasing the launch angle by as much as 3* over what the loft/CG and angle of attack determine. And this is ONLY for wood shafts, not iron shafts because in terms of REAL BENDING AMOUNT, all iron shafts are much stiffer than all wood shafts due to their shorter length + larger tip section diameters. Again, if a golfer perceives a LOT HIGHER flight with a different shaft, in addition to this amount of forward bending that can be generated, it is eminenly possible the shaft's contribution to the overall and total feel of the club will have caused swing moves that resulted in a more upward angle of attack into the ball.
I can;t stress this relationship of the overall and total feel of the club to how the golf swing changes/adjusts to cause results that are not specific to the shaft's bending or shaft's real performance.
Anyway, this is way too long already - I can tell that I got the old passion for sharing what we know going a little too much. If this triggers questions, fine, I will be happy to share any answers I know as well as tell you that we may not know that yet. But overall, do please keep in mind that
1. the same shaft reacts totally different to different swing transitions, downswing acceleration, wrist **** release points
2. the shaft is ONLY a product of its weight, torque, balance point, length and overall stiffness as defined by its bend profile - things like material or manufacturing differences DO NOT AFFECT ITS PERFORMANCE, but they DO AFFECT ITS FEEL, which in turn can affect the golfer's swing moves
3. The shaft can only affect the total weight/swingweight of the club, contribute with the loft/CG of the head to determine the final launch angle but only for golfers with a somewhat later to very late release, contrinute slightly to accuracy based on its torque vs the golfer's transition and downswing acceleration.
this last wee parcel of info is NOT for Scootie as it is too technical BUT the ol engineer Pat will understand ----------
this isn't from Wishon
- The average time from the initiation of the down swing to impact is 0.3 - 0.4 seconds.
A typical "stiff" shaft measures at ~ 260 CPM. What we're really care about is 0.5 cycles, (0 deflection - maximum negative deflection - 0 deflection).
This half cycle would then take 260 / 60 * 2 = 8.67 half cycles per second, or 0.115 seconds per half cycle. |
