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Taking the guesswork out of selecting shafts (Part 1)

by   (Senior Writer I)   |   September 20, 2012
golf shafts

This is part 1 of Tom Wishon’s three-part series on shafts. Part 2 Shaft Fitting- Guessing to SpecificsPart 3 Facts about shafts- What they do

It’s clear that a lot of threads and posts on GolfWRX.com are from golfers asking all sorts of questions about shafts. In nearly 40 years of golf equipment design and research work, I think it is fair to say that the shaft is the least understood component of the golf club. Since I have engaged in serious shaft research since 1990, and from that have learned a lot about shaft design, performance and fitting, I would like to help clear some things up and share some facts about shafts and what you need to know to pick the best shaft for YOUR swing.

I will do my best to make all of this understandable without stressing everyone’s attention span. But there is a lot to explain about this subject so I will separate this into three parts with some time in between each thread to allow you to digest it and ask questions.

Click here for more discussion in the “Clubmaking” forum.

How Can Golfers TRULY Compare Shafts to Know their Real Performance Differences?  

Below is a typical “specification chart” from a major shaft company.  I have removed the names because it is not my intent to criticize a specific shaft maker.  It is simply my desire to show you how the typical information provided about shafts will not allow golfers to know what they really need to know about shafts to be able to make an informed buying decision.

Shaft Company chart 1.JPG

Plain and simple, the information in this chart cannot tell a golfer how any of these shafts truly perform, much less how they actually compare in stiffness to any other the shaft.  The Flex?  There are no standards for exactly how stiff any of the flex letter codes are.  Charts like this provide no quantitative measurements of exactly how stiff any shaft might be.

In fact the ONLY bits of information on a typical chart like this which can be helpful are the WEIGHT and the TORQUE.  The Butt and Tip Diameter?  These are fine for knowing what the hosel bore of the clubhead needs to be to easily accept the shaft and to know how to install the grip to obtain a desired size.   The Parallel Tip section?  That simply tells you if you cut more than 2” off the tip, it’s not likely to fit all the way into any normal hosel with a 0.335” bore.  The Bend Point?   Sorry, but the term bend point is not relevant because with terms like “high”, “mid”, or “low”, it has always been way too generic.  WHERE EXACTLY IS a mid bend point?   And how does this mid bend point compare to some other company’s mid or low or high bend point?

Recently I have seen a couple of other shaft companies begin to offer a form of QUANTITATIVE stiffness measurements for their shafts.  Here’s an example:

shaft company chart #2.JPG

This shaft company offers a series of “Stiffness Profile” measurements for the Butt, Mid and Tip sections of their shafts.  That’s a start but the problem is, this company only offers these Stiffness Profile measurements for their own shafts.  This is somewhat reasonable for comparing the various shaft models and flexes within this one company, but what if you have some other company’s shaft in your driver, or you wish to compare these shafts to some other company’s shafts?  And if you have never hit one of these shafts, how stiff or flexible are any of these measurements in the first place?   These rudimentary Stiffness Profile measurements do not allow the depth and scope of stiffness information to allow you to make a valid shaft fitting decision.

You might look at the Butt Stiffness number and say, “That’s a frequency measurement and I know how stiff a 270cpm shaft plays.”  Yes, that Butt Stiffness number is a frequency measurement.  But the problem is you have no idea how these butt frequency measurements were obtained.  What length of the butt was clamped? How heavy was the tip weight? Is this 270cpm frequency the same as a 270cpm shaft that you played?  Again, there are no standards in the golf industry for shaft frequency measurement so you have no idea if a measurement of say, 270cpm from this company is equivalent to a measurement of 255cpm or 265cpm or whatever cpm using one of the many other types of shaft frequency measurement.

What makes all this even more “exciting” or I should say, challenging, is the fact the industry is now populated with many shafts which are VERY expensive. Do you really want to GUESS whether that $300 shaft is right for you, or would you like to have a more definitive way to help make that decision?

Click here for more discussion in the “Clubmaking” forum.

Is there a Better Way to Compare Shaft Stiffness?  

Ever since I began to perform quantitative measurements on shafts, I knew we needed a way to be able to see and compare the stiffness of as many shafts as possible, and do it over their entire length.  That way clubmakers and golfers could have a tangible way to compare the complete full length stiffness design of shafts to each other.  The performance and the bending feel of any shaft are products of its stiffness design over its entire length. Not just the butt, not just the tip, but the whole length of the shaft. There are almost an infinite number of ways the stiffness of a shaft can be created over its entire length.

In 2005, we arrived on a reasonably simple method to perform full length comparative stiffness measurements for golf shafts.  From this we created a software program that would house and display the data from our shaft stiffness comparison methodology.  We made the first version of the software available to clubmakers in 2006.  Two times each year we ask the shaft companies to send us multiples of each of their new shaft models and flexes so we can keep adding shafts to the software data base.

At present we have well over 2,000 different wood, hybrid and iron shafts in the TWGT Shaft Bend Profile software.  We charge a one-time fee of $129.50 for the software because the expense to have it programmed and maintained is not insignificant.  It also takes us quite a number of hours to acquire, test and input the new shaft data into the software two times each year.  You can find more information about this on my site, which is linked in my bio.

As much as we would like, there is no possible way we can include EVERY shaft in the industry in the software’s data base.  We have to rely on the shaft companies to send us the multiple samples of each of their shafts to measure because we simply cannot afford to actually buy all of the shafts. We also cannot obtain the OEM stock shafts because the OEM companies will simply not allow anyone to have their raw shafts for any measurement work like this. We do have some OEM stock shafts in the data base which come from “pulls” from OEM clubs that we can measure. But we do try to put as many shafts as we can into the data base so that clubmakers and golfers can better compare the relative stiffness of shafts.

To date more than 600 different clubmakers now use the TWGT Shaft Bend Profile software in their shaft fitting.  This use by the clubmakers has also provided “in the field” verification that the measurements of the shafts do indeed provide a valid representation of the performance and even the bending feel of the shafts in the data base. The shaft fitting comparisons made with the data in the TWGT Shaft Bend Profile software is most definitely valid for predicting the performance and feel of a shaft.

How Does the Bend Profile Data Explain the Performance and Differences Between Shafts?  

Some of you have seen graphs from the TWGT Bend Profile software that I have posted to answer a question here and there about shafts.  For those of you who have not seen this, following is a basic screen image from the software showing a comparison of the relative stiffness design of two shafts – I just randomly chose to use the Diamana White 83 X5CT S flex and the UST ProForce V2 HL65 S flex to start the explanation.

You see 7 columns in the data box.  These show WHERE on the shafts we do the stiffness measurements.  Starting at 11” up from the tip, the measurements then are made at 5” spaced positions up from the tip end of each shaft, ending at 41” up from the tip.  Because iron and hybrid shafts are shorter in raw length, their measurements run from 11” up to 36” up from the tip end of the shafts.

Measurements are done with a 454 gram weight attached to the tip of the shaft using a specially designed frequency analyzer that measures the shaft oscillations using two separate load cells and two separate strain gauges.  Each shaft is tested at the same exact place on the shaft, using the same exact test methodology.  This ensures the data is comparable from shaft to shaft to shaft in the data base of the software.

Let’s take a look at an example graph and data chart:

WRX shaft article graph 1.JPG

The 41”, 36” and 31” measurements represent the butt section, the 31”, 26” and 21” the center section and the 21”, 16” and 11” measurements represent the tip section of the shaft (yes there is an overlap). When companies design different flexes of a shaft, each different letter flex version is ordained chiefly by the stiffness measurements of the 41 to 21 inch positions (butt to center to upper tip) of the shaft.  Tip section differences on shafts do not play a significant of a role in the overall flex design (swing speed rating) of a shaft as do the butt to center to upper tip sections.  The tip section design of a shaft is chiefly designed to create differences in the launch angle, trajectory and spin rate among shafts within the same flex.

After significant research and study of the shaft data, we can make conclusions about how much of a difference in the stiffness measurements is significant or not.  With so many shafts in the data base, we can also identify a basic relationship between a golfer’s clubhead speed, the average bending force generated by that clubhead speed, and the overall stiffness design of a shaft.  This is very important for being able to tell a golfer which shaft may be better suited to his clubhead speed.  Therefore we can use the stiffness measurements of the 41” to 21” positions on the shaft to determine the swing speed rating of any shaft.

We can also determine how much of a measurement difference is significant or not with respect to stiffness in the butt, center and tip sections of the shafts.

  • For example, at the start of the butt section as represented by the 41” measurement, a measurement difference of 8 to 10 cpm is approximately equivalent to one full letter flex difference.
  • At the middle of the center section as represented by the 26” measurements, a difference of 12 to 15 cpm is equivalent to one full letter flex difference.
  • In the middle of the tip section, represented by the 16” measurement, a difference of 30-40 cpm usually accounts for a visible difference in the launch angle, trajectory and spin rate of the shot.

There are no standards for how stiff any of the letter flex designations of shafts may be.  How stiff  IS an R flex, an S flex (or any of the other letter flexes)?  How much variation is there among shafts of the same letter flex?    

Below is data to show the low to high range in stiffness for all shafts for drivers and fwy woods in our data base that are marked as being a letter R flex shafts.  These are listed from softest to stiffest, but all of these are made and marked by their respective companies to be an R flex shaft.  Based on the measurements of the 41/36 for the butt section, you are looking at a range of FOUR FULL FLEXES.   That means the R flex shafts in the golf industry actually exist within a range of 4 full flexes.  The same is true for S flex shafts as well.  Because there are far fewer L, A and X flex shafts the range in stiffness within these letter flex codes is not quite as wide as it is within the R and S flex shafts created by the golf industry.  Here is the Bend Profile graph and data chart to illustrate the range in R flex shafts for woods that exist today.

WRX article shaft graph 2.JPG

Based on all of our research to associate a driver clubhead speed with the measurements for the 41, 36, 31, 26 positions of the butt and center of the shaft, here are the appropriate driver clubhead speed ratings for each of these above 5 different R flex shafts:

Miyazaki C.Kua 39 R – for a golfer with a driver clubhead speed of 55 to 65mph
UST ProForce V2 HL-55 R –     for a golfer with a driver clubhead speed of 65 to 75mph
Aldila RIP’d NV65 R – for a golfer with a driver clubhead speed of 75 to 85mph
Fujikura Blue 004 R –     for a golfer with a driver clubhead speed of 85 to 95mph
Rappor Blue Velvet R – for a golfer with a driver clubhead speed of 95 to 105mph

Therefore, you are looking at shafts in the golf industry which match up to a range in swing speed of 50 mph – yet ALL are marked and sold as R flex shafts.

You may be prompted to comment, “this has to be the exception rather than the rule.”  If we take a look at the data base to search where the majority of R flex marked shafts lie with respect to their 41/36/31 inch butt section measurements, we find that the majority of R flex shafts exist within a range that represents a 20 to 30 mph difference in the clubhead speed rating for the shafts.

This is precisely why golfers sometimes buy a new club and its shaft doesn’t feel as stiff or feels stiffer than their previous shaft with the same letter flex.

Do all shafts of the same letter flex have the same butt to center section stiffness (same swing speed rating) within the same shaft company or the same golf club company?  

Let’s take a look at the R flex version of a number of different shaft models from one shaft manufacturing company.   All are selected on the basis of being very close to the same shaft weight so they potentially could be considered for purchase by the same golfer.

WRX article shaft graph 3.JPG

Let’s be sure to first make something clear – We are NOT saying it is wrong for a company to make the same letter flex version of each different shaft model to be of a different stiffness design.  That is their right as a company to determine the exact design of each flex for each shaft they make.

What we are saying is that it is very difficult for consumer golfers to know how to choose what shaft might best match their swing when the companies provide no empirical information like this to use for making quantitative comparisons of the different shafts.

The swing speed range for all these R flex shafts from Aldila ranges by 25 mph.   At one end, the NVS 65-R is a shaft that would be rated for use by a golfer with a driver clubhead speed of 70-80mph.  At the other end, the RIP Gamma 60-3.6-R is a shaft that would be rated for use by a golfer with a driver clubhead speed of 85-95mph.  That means within all the R Flex shafts from Aldila, the clubhead speed rating for possible selection by a golfer can range by 25 mph – yet all are marked as being an R Flex shaft.

On top of this are definite differences in the TIP SECTION design of all these different R flex shafts.  Within all the R Flex shafts from Aldila, we see shafts with a tip section design that ranges from the very tip-soft Habanero 60-R all the way up to the moderately tip stiff design of the RIP Gamma 60-3.6-R. If both these R flex shafts were hit by the same golfer, the Habanero would launch the ball approximately 3* higher and with an estimated 750 rpms more backspin than the RIP Gamma 60-3.6-R – yet again, both are marked as R flex shafts.

Once again, we must reiterate – WE ARE NOT SAYING THERE IS ANYTHING WRONG WITH THESE SHAFT DESIGNS nor are we criticizing anything about them. Each company is free to design their shafts as they see fit, for whichever golfer swing types they designate.  However, how can any golfer really know the difference in the overall stiffness design of any of these shafts and from that, know anything about the performance difference between these shafts of the same flex without clear, quantitative comparative information?

Please understand that variation between the same letter flex of different shaft models goes on INTENTIONALLY with every shaft company in the golf industry. It is not specific to Aldila. I simply use them to illustrate that this does happen within each shaft manufacturing company. Without a clear, quantitative means to compare the stiffness design of shafts, consumer golfers are in the dark with respect to making accurate shaft buying and shaft fitting decisions.

(In part 2 we will discuss How a golfer should select the right shaft for his/her swing)

For those of you who made it this far, CONGRATULATIONS!!   You ARE indeed interested in shafts.  For those of you who didn’t … well, true shaft knowledge can be a little beyond a normal realm of interest, I do admit that. I hope you all got something out of this, and there is more to come to help you know much more about how to determine the differences between shafts and how to turn that information into better shaft buying decisions.

By the way, there are many custom clubmakers out there who can help you find the right shaft FAR more accurately than the ways you have been trying to pick the right shaft in the past. These clubmakers who study this stuff are worth knowing and can help you.  Again, to find a good clubfitter, check out these sources: The AGCP (Association of Golf Clubfitting Professionals) -  http://www.agcpgolf.com/locator/ , The ICG (International Clubmakers’ Guild)  - http://www.clubmaker…uild-google-map and The TWGT Clubmaker Locator at - http://wishongolf.co…d-a-clubfitter/ .

Click here for more discussion in the “Clubmaking” forum.

Click here to read part 2 of Tom Wishon’s series, “Taking shaft fitting from guessing to specifics.”

About

Tom Wishon is a 40-year veteran of the golf equipment industry specializing in club head design, shaft performance analysis and club fitting research and development. He has been responsible for more than 50 different club head design firsts in his design career, including the first adjustable hosel device, as well as the first 0.830 COR fairway woods, hybrids and irons.

GolfWRX Writer of the Month: February 2014

Tom served as a member of the Golf Digest Technical Advisory Panel, and has written several books on golf equipment including "The Search for the Perfect Golf Club" and "The Search for the Perfect Driver," which were selected as back-to-back winners of the 2006 and 2007 Golf Book of the Year by the International Network of Golf (ING), the largest organization of golf industry media professionals in the USA.

He continues to teach and share his wealth of knowledge in custom club fitting through his latest book, "Common Sense Clubfitting: The Wishon Method," written for golf professionals and club makers to learn the latest techniques in accurate custom club fitting.

Tom currently heads his own company, Tom Wishon Golf Technology, which specializes in the design of original, high-end custom golf equipment designs and club fitting research for independent custom club makers worldwide Click here to visit his site, wishongolf.com

24 Comments

  1. Pingback: Does the golf shaft really effect your shots? | golfblogaustralia

  2. Adrian Hubert

    March 31, 2013 at 11:20 am

    Hi,

    I have some good knowledge of shafts, please can someone confirm that there is a difference between buying a shaft from say Golfsmith and having the same branded shaft from the tour. ?

  3. Tom

    March 11, 2013 at 5:38 pm

    Great article Tom. Just wondering, how did you determine that 454 grams was the best weight to use?

  4. tlmck

    October 8, 2012 at 10:09 pm

    lol. Just thinking of the guy who tried to sell me a C.Kua 39 R for my 92mph clubhead speed.

    I can say for certainty, with only my swing as evidence, that a C.Kua 39 stiff is equivalent to a Diamana Red 44L stiff. I have the C.Kua in my identical head backup driver as the Diamana is apparently no longer made, and was nowhere to be found. It’s also nice that the C.Kua does nor require a special grip.

  5. Nathan

    October 2, 2012 at 3:56 am

    This article looked promising untill i got to the part ( you really want to know it will cost you!!) good work

  6. Chris

    October 1, 2012 at 9:39 pm

    When can we expect part 2?

  7. Tom Wishon

    September 26, 2012 at 5:25 pm

    to JEFF who asked about shaft swing speed ratings for golfers with different levels of transition/tempo force in their swing.

    Most definitely you are sniffing at a lot of what is going to be in Part 2 of this series. This is precisely why we teach clubmakers to do a basic 1, 2, 3 rating of each golfer’s transition force and downswing tempo to go along with their swing speed.

    For example, three golfers all with a 90mph swing speed. But Golfer #1 has a very forceful transition and aggressive tempo. Golfer 2 has an average force/aggressiveness in transition/tempo and Golfer 3 has a smooth, more passive “swinger” type of transition and tempo.

    For golfer 2, you can choose from shafts rated to be 85-95mph because his bending force is average for a 90mph swing. For golfer 1, you’d pick from shafts rated at 90-100 because these would be slightly stiffer shafts his swing speed is at the low end of the shaft’s rating – more stiff to better match with the fact that for his 90mph swing speed, his strong/forceful transition/tempo puts more bending force on the shaft so he needs a little stiffer shaft than what his swing speed indicates on its own.

    And then finally the 90mph smooth swinger should pick from shafts with a swing speed rating of 80-90mph because he is NOT putting as much bending force on the shaft for his 90mph swing.

    But you have the big basic point of shaft flex fitting down – amount of bending force is not always related to the golfer’s swing speed, but is heavily influenced by their transition and downswing tempo.

  8. Tom Wishon

    September 26, 2012 at 5:04 pm

    To John who asked about OEM stock shaft stiffness:

    There’s no nice way to say this. You can’t and won’t know how stiff an OEM stock shaft is. The OEMs do not provide any quantitative information on the stiffness/bend profile design of their stock shafts. Test hitting is the only way unless you buy the club, take it apart and then send me the shaft so I can measure it and include it in the data base of the software we created.

    We’d love to include them in the data base of this software program but they will not send us their stock shafts to measure, nor will they allow their shaft mfg vendor to do that either. So the few OEM stock shafts we have in the software come from clubmakers who pull these shafts intact from stock clubs and send them to us to measure.

    This again is one more good reason to be working with a GOOD, experienced clubmaker who has this software when you want to nail down what works/performs best for your swing and sense of feel.

    • Ian Mikutel

      April 22, 2013 at 4:18 am

      Why not use some of the $129.50 you charge for database access to purchase OEM shafts each year? It seems to me like the most valuable data for most golfers out there would be that of the OEM shafts, not super expensive, custom shafts? Unfortunate that the OEMs won’t send clubs for this testing, or just standardize this testing across all OEMs.

  9. Pingback: GolfWRX.com – Taking the guesswork out of selecting shafts (Part 1) | Golf Products Reviews

  10. Pingback: Light VS heaver shafts or clubs??? - Page 2 - Golf Forum - Golf Rewound is the Family Friendly Golf Forum and Discussion Group

  11. Justin

    September 24, 2012 at 11:36 pm

    @Eric:

    Yes, the more flexible the shaft, the more you can “feel”.

  12. Ryan

    September 22, 2012 at 4:17 pm

    Great write up. This definitely confirms what a lot of us already thought we knew which was every OEM even within there own shafts has no tangible way of discerning flex even within their own shafts that to me is CRAZY but soo glad Tom gave us real eveidence to prove this and I cannot wait for part 2

  13. Ryan

    September 22, 2012 at 4:14 pm

    Great write up. This definitely confirms what a lot of us already thought we knew which was every OEM even within there own shafts has no tangible way of discerning flex even within their own shafts that to me is CRAZY but soo glad Tom gave us real eveidence to prove th

  14. Jeff

    September 21, 2012 at 8:24 pm

    Terrific article. Does the data about stiffness profiles lend itself to discerning which shafts are more suitable based on an individual’s loading characteristics at a given swing speed? Does this matter? Looking forward to reading your next article.

  15. Eric

    September 21, 2012 at 5:17 pm

    Tom:

    I play hickory clubs with a group. One thing I’ve noticed is one can truly feel the weight of the club, and I believe that significantly affects how the club is swung – particularly as you begin the forwardswing, and your subconscious changes the path of the swing.

    As a result, I wonder if the whippier shafts improve feel of the clubhead – OR – is there a way to get great clubhead feel without giving up the control of a stiffer shaft?

  16. Mark

    September 21, 2012 at 3:06 pm

    Thanks Tom.

    As always, a well thought out and informative article. I’ll be getting the software, and look forward to part 2.

  17. ACGOLFWRX

    September 21, 2012 at 8:42 am

    Excellent information for the masses, well written and above all, very informative.

  18. John

    September 21, 2012 at 6:16 am

    Very well written Tom – thanks. The only problem remains, how do I know what level of stiffness I should be purchasing through the OEM’s at retail stores? Hope that’s covered in Part II.

    • Al

      October 16, 2012 at 11:47 pm

      Not speaking for Tom by any means, but his philosophy is that, rather than relying on the OEM’s, you should be custom fitted for your clubs rather than buying off the shelf.

  19. Matt

    September 20, 2012 at 10:50 pm

    As an engineer I am fascinated by this and am always on the search for the right fit as a scratch golfer, to maximize my game. This is revolutionary stuff. Thanks!

  20. Bill B

    September 20, 2012 at 8:54 pm

    Tom,

    Without a doubt this is the best information on shafts I have seen in one place. You have created my dream of the “golf shaft genome project”. The golf shaft is the heart of the club and you are making quantative information available that provides options to professional fitters and club junkies alike. We have all made our own personal golf shaft assments on various shafts via real life play, launch monitor results, and feel, but this speeds up the process and opens the door to choices across various manufactures.

    Thanks and keep up the good work

    Bill Baitinger

  21. Mike D.

    September 20, 2012 at 12:50 pm

    Thanks for the write-up Tom. Verifies what I’ve thought about shaft manufacturing. Can’t wait to see part two!

  22. Chris

    September 20, 2012 at 12:35 pm

    This is absolutely fantastic information. Many thanks!.

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