Changing Golf Shafts – Do I Use The Same Flex for Different Shafts?

Sometimes and then again, sometimes not. Sorry but that’s the truth because there are no standards in the golf industry for how stiff any of the letter flex codes are. Never have been and never will because the various golf companies don’t want that. So the R flex from one company can have the same stiffness as the S flex from another company or even the same stiffness as the A flex from a third company. Not only that, but the same flex of different shaft models within the SAME company is not necessarily going to be the same stiffness.

Sound a little confusing? Or a little bit like that’s not the way it should be?

Actually, it’s fine if each golf club company or shaft company wants to design their shafts different than another company. In doing that, they can express their own beliefs for each of their shafts should be designed.

What’s messed up is the fact that virtually none of these companies provide golfers with specific information to tell them exactly how stiff their shafts are in comparison to any other shafts. When it comes to flex, golfers are literally kept in the dark and have to adopt a “trial and error” means of determining how stiff this or that shaft is and whether it fits the golfer or not.

Since there are numerous shafts in the industry today that cost $100, $200, $300 and even more, a trial and error approach to shaft selection can get more than a little expensive. What’s the alternative? To put your shaft fitting needs in the hands of a custom Clubmaker who works with Tom Wishon Golf Technology’s proprietary shaft bend profile software.

In short, many years ago we saw the need for quantitative shaft stiffness information and created not only a measurement methodology for shaft stiffness, but a software program to allow all shafts in our data base to be compared in a way that you can definitely compare the stiffness design of many different shafts. As of mid 2012, we have over 2,000 different shafts in the TWGT Bend Profile software data base.

Here’s an example of what the information in the TWGT Bend Profile software looks like and how it works. The following data shows the range in stiffness among shafts which are sold and marked as R Flex in the golf industry today.

To translate what you are seeing, if we apply a swing speed rating to each shaft, you are looking at R flex shafts which range in swing speed rating from a 55-65mph shaft all the way up to a 110-120 mph shaft. The same goes on within all the S flex shafts in the industry as well.

Bottom line? If you want to be fit as accurately as possible for the shafts in your clubs, go get fit by a good, experienced custom Clubmaker. Especially a Clubmaker who uses this software in their shaft fitting. Clubmakers who use our TWGT Shaft Bend Profile software do a better job of fitting golfers and have a very high percentage of golfers who never have to go through an expensive trial and error process to find the best performing shaft for their swing.

-Tom

How Does COR Affect Your Golf Game?

Companies, organizations and industries love to use acronyms because these abbreviations of longer terms can so easily roll off the tongue.  One that has been a buzz-acronym in the golf equipment industry since 1998 isCOR – short for Coefficient of Restitution.

Experienced golfers know the COR is a number which represents how “hot” the face of their clubhead(s) is made – or rather how much distance they can get out of the shot for their swing speed.  COR made its way into the golf industry’s vernacular back in 1998 when the United States Golf Association got freaked out at the distance the pros were hitting the ball.  Acting before ever doing any testing, the USGA blamed the pros’ distance increase on the use of the relatively new (at that time) titanium drivers and enacted a rule that placed a limit on the COR of all driver faces.

COR is actually a measurement of the energy transfer in a collision of two objects.  It can be expressed in a number between 0 and 1.  For example, when the USGA put a COR limit of 0.830 on driver faces, that meant no driver would be deemed to be conforming to the rules if more than 83% of the energy in the collision of the driver head with a golf ball were transferred from the head to the ball.

COR is actually a measurement of the energy transfer in a collision of two objects.  It can be expressed in a number between 0 and 1.  For example, when the USGA put a COR limit of 0.830 on driver faces, that meant no driver would be deemed to be conforming to the rules if more than 83% of the energy in the collision of the driver head with a golf ball were transferred from the head to the ball.

The COR rule also became known as the “spring face rule.”  This was a little unfortunate because in fact, a higher COR clubface does not really act like a spring.  When you think of spring face, it is easy to think that the ball causes the clubface to flex inward, and upon flexing back out the ball is propelled as in the manner of a trampoline sling shotting a gymnast up.

Actually, higher COR faces work like this.  In the collision of the clubface and the ball, there is always some energy lost.  This is because the face flexes inward and the ball is compressed against the face.  Both actions result in a loss of energy.  Of the two, the ball loses by far the most energy when a shot is hit because it can squash as much as 30% of its diameter against the face of the driver.  In a normal shot hit with an old thick face stainless steel metal wood, scientists estimate that 80% of the energy loss in such an impact came from the ball while the balance of 20% came from the clubhead.

The idea of a higher COR face design, whether done for a driver or any other clubhead, is to allow the face to flex inward a little more so that the ball is not compressed as much against the face.  When that happens, the face loses a tiny bit more energy because of its increase in face flexing.  But the ball then loses a lot less energy than before because it is compressed so much less because of the slight increase in face flexing.

The net result? The ball takes off at a higher velocity and flies farther for the same clubhead speed and same loft angle on the clubface.  Hence high COR means more distance regardless of your clubhead speed.

And that’s how that acronym really works in the design and performance of a golf clubhead.

-Tom

Golf Grip Size – How Crucial Is Grip Size to Your Golf Game?

In a word?  Playing with the right grip size is HUGELY important.  If the grip is too small and the golfer has to wrap his hands too far around the grip, the muscles of the forearm tighten up.  When the forearm muscles get tighter, it becomes much more difficult to take the club away from the ball smoothly and then becomes more difficult to achieve a consistent swing tempo and swing rhythm.

If the grip is too large, this can impede a proper release of the wrist-cock angle on the downswing which also can prevent us from rotating the face back around to square on the downswing.

Over the years, there have been several guidelines created by various golf companies or by people who perform Clubfitting research for measuring the size of the hands and fingers, from which a proper grip size is recommended.

In addition, it has also been taught that the proper grip size is achieved when the golfer closes their hands around the grip and the finger tips come just short of touching the base of the hands.  As a starting point, such charts or overlays for the hand are fine.  But ultimately each golfer has to decide what their MOST COMFORTABLE grip size should be.

In short, if a hand and finger measurement chart says the grip should be one size and the golfer prefers a different size because it is more comfortable, you go with the decision for comfort – regardless what the golfer’s handicap or playing ability might be.  Give you a good example.  On average, my wife Mary-Ellen shoots between 95-100.  Via her hand and finger measurements, she comes up on the chart for a women’s +1/64 oversize grip.  Yet she much prefers and can keep her grip pressure most constant and comfortable with a men’s standard size grip.  That’s the grip she plays and that’s the grip I agree as a veteran Clubfitting research person that she should play.

Perhaps the best way for clubmakers to fit grip size for comfort is simply to keep a set of different grip size samples either on cut of shaft pieces or better yet, installed on actual golf clubs.  Gripping a cut off shaft section can fall a little short of giving the golfer a real sense of what a particular grip size will feel like when installed on a full length golf club.  Most people have enough old clubs laying around that it would be possible to use them as your grip size samples for grip size fitting.

Remember – grip size for COMFORT FIRST so the hands and arms can maintain a secure hold on the grip without excess grip pressure or muscle contraction in the forearms.

-Tom