The Known Spec
Most of the specs of your golf clubs remain a secret from you playing partners. No one in your group will ever know the loft of your six iron, the length of your driver, or if the grooves on you wedges are conforming.
The flex of your shafts is an exception. With a quick glance, your buddies can see if you’re playing something “manly” or if you’re a “soft-swinging wimp.” And because it’s so visible, many golfers choose their shaft flex based on ego.
We wanted to know if this matters to the performance of the clubs. Are players trading yards and accuracy for an ego boost?
The Myths
Myth #1 – More flexible shafts produce more distance
Myth #2 – Stiffer shafts are more accurate
Myth #3 – More flexible shafts promote a slice
Myth #4 – Faster swingers always need stiffer shafts
Myth #5 – A properly fit shaft promotes more distance and accuracy
How We Tested
For this test, we brought together six golfers, ranging in handicap from 10 to scratch. Each player chose a 6-iron head and hit seven shots each with three different shaft flexes – regular, stiff, and x-stiff. All of the shafts were the same model. All shots were recorded on Trackman. No shots were deleted.
All testing was done at, and with the help of, Club Champion.
The Results
The data that we collected shows that it is plausible that a softer or more flexible shaft can produce more distance. In our group averages, the regular flex shaft created a little more club head speed, more ball speed, and a slightly higher smash factor. All this translated to a total distance that was 2 yards longer than the x-stiff and 5 yards longer than the stiff flex. Additionally, four of our six testers produced their longest shots with the regular flex shaft.
We rate this myth plausible and not confirmed for two reasons. First, there were fewer mishits (shots with below 1.2 smash factor) with the regular flex shaft. One could argue that’s a product of the softer shaft, but I don’t think it’s a causal link. Second, if softer shafts inherently produced longer shots, we would have seen the stiff flex produce more distance than the x-stiff.
The idea that stiffer shafts are more accurate is busted. Our testing actually showed the opposite: the regular flex shaft was the most accurate of the group.
When we look at the individuals, we see that accuracy is a matter of fit. Some players were most accurate with regular flex, others with stiff, and some with x-stiff.
This myth is a personal “favorite” of mine, having heard it from countless golfers when I worked retail. I am happy to say that it’s busted. When hitting the most flexible shafts, our testers were either very accurate or prone to hooking the ball. The only substantial right-sided miss in our whole test group came with a stiff flex shaft.
One of the most interesting and surprising findings is that there is not a direct correlation between swing speed and shaft flex. Players 2 and 3 provide a great example: they both fit best into a regular flex shaft but their swing speeds are 20 MPH different!
There are numerous reasons why this is true. First, flex is only one variable in fitting. Shafts can have the same flex but different weight, bend profile, or torque. Also, the player’s tempo has a big impact on how they load the shaft. A player with a slower swing and aggressive tempo may bend the shaft just as much as a player with a faster swing and slower tempo.
While the data here is not nearly as neat and clean as I’d expected, I believe that it does make the case that being fit for the right shaft will give you more distance and accuracy. If you look at each player individually, you will see that each one has one flex that clearly outperformed the others. Four of the six testers found that one shaft produced their longest and straightest shots. The other two golfers found two shafts that performed very similarly.
Player 1 provides a strong example of the value a good fit. Switching from regular to stiff helped him gain over 7.5 yards of total distance and brought him 6 yards closer to the target. Player 2 had similar accuracy with two shafts, but one was 11 yards longer. Player 3 improved his accuracy by 7 yards and his distance by almost 6. Finally, Player 6 was 6 yards more accurate and 16 yards longer when moving up from stiff to x-stiff.
Other Findings
The one unusual thing that we saw in our data is that several players performed well with regular and x-stiff but not stiff. This can be seen in Player 2’s accuracy, Player 3, Player 4, Player 5, and Player 6. Some of this can be chalked up to mishits, but some of it holds in spite of mishits.
My guess is that these players performed well with the correct fit and could compensate for a really poor fit but couldn’t adjust to a fit that was slightly off. Think of it this way: if someone gave you a club with a droopy rubber shaft, you would sense immediately that it felt “wrong,” and you’d focus on adapting to it. With a club that’s just a little off, however, you might continue making normal swings without being able to sense what’s going wrong. Again, this is just a guess and we may revisit this in the future to learn more.
Conclusion
The choice is yours: you can let your ego select your shaft flex, or you can choose to hit longer, straighter shots. The evidence we gathered clearly shows that shaft flex is a critically important variable in choosing the right clubs, and fitting it is not as easy as finding your swing speed on a chart. Make an appointment with your local club fitter and see if, like our testers, you can gain up to 16 yards of extra distance.
The Data
Matt lives in the northwest suburbs of Chicago with his wife and two daughters.
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Great info. Well thought out. Now if I can get down to a 10 handicap.
You have not mentioned purring of the shafts in your test; Could it be that if not purged, the dispersion results of the various shafts could differ because of an ill alinement of the shaft to the heads?
Nigel,
None of the shafts were PURE’d. Each one was disconnected and reconnected to the head before each test, so I don’t think orientation was a significant factor.
-Matt
Did anybody get the frequency of the 3 flexes? According to my system and frequency charts a 6 I R flex @ 292, S flex @ 305 and X flex @ 318 cpm. My system allows for tempo .9, 1.0, 1.1, 1.2, 1.3, 1.4 I give .9 tempo a total of 7.5 cpm’s higher than a 1.4 tempo, load at the top. 10 cpm = 1 flex. In my system 13 cpm’s between flexes would be 1 and a 1/3 rd flex. If the same person hits these 3 flexes there will be a progression, they will be sequential. You would have to think that the S flex wasn’t a S flex. Nobody hits a R and X well and struggles with a S
Ollie
2
Ollie,
The point of running these tests is to find out what “common sense” things, such as “Nobody hits a R and X well and struggles with a S” are true and which ones are not.
Best,
Matt
Good report. I would be interested in seeing a similar test with different iron shaft weights (e.g. 85, 105, 125 g) . I always used S300 shafts. The most recent irons I purchased have an 85 gram shaft and I feel like my control has suffered and there is more variability in distance as well.
Anthony,
We did a test on shaft weight here: https://pluggedingolf.com/how-important-is-shaft-weight-golf-myths-unplugged/
Best,
Matt
Interesting test. Just one thing. Most sites that do “offline” numbers do as you have done here. Add up and numbers and divide. But a +5 and -5 don’t count each other out on a golf course. Whether they are right or left 5 yards, they are still offline. So Reg should be 6 offline and X should 4.5 based on your sample. True?
Jason,
Good catch. I calculated the offline correctly for the individuals (not having positives and negatives cancel each other), but made a mistake with the group averages. Thanks.
Best,
Matt
I’m confused. You stated that each player tested a regular, stiff and x stiff shaft. Yet, the photo depicts a senior, regular and stiff flex. Was that a stock photo or the actual shafts used?
Thanks.
Reginald,
That’s just one of our stock pictures.
Best,
Matt
Hi, just need to know, who is the standard clubs off the store shelf is for? I’ve been told more than once, that those would suit me just fine, because of my height 5.6 and swing, off a board for loft and lie, am not sure what the point is ??
DJ,
The answer of “Who is it for?” varies from club to club because there are no standard specs in the golf industry. Even if there were standard specs, it wouldn’t be correct to say, “This is for everyone who is 5’10” because there are different body types and swings. Finally, lie boards are not a good way to choose your clubs’ lie angles.
Best,
Matt
Hey Matt. I just got fitted for the m3 3 wood 60 gram shaft. I’m not hitting a big pull. Should I go back and get fit for a heavier shaft
Jonathan,
2 questions:
1) How were you fit?
2) How long have the big pulls been an issue?
Best,
Matt
Do you think this same expirement would have the same, or similar, results?
Daniel,
Are you asking if I think these results are repeatable? Yes, I do.
Best,
Matt
Sorry I left out, for hybrids. Do you believe if they used hybrids/woods it would be similar results?
Thanks
Daniel,
Yes, I think the results would be similar across all club types.
Best,
Matt
Based on a 5 iron steel shaft flex stiff versus regular. How much effect does each one have to lie angle at impact
I wonder if shaft flex becomes more important the higher one’s handicap is? With better players maybe it’s not as much a factor?
Kent,
I believe that across all dimensions of fitting, a better player can adapt to poorly fit equipment better than a less skilled player.
Best,
Matt
I note this is an old article but still relevant in 2021.
My own opinion is that the test should have been done using a robot thus eliminating any human inconsistencies. Furthermore I can’t understand why anyone would want the shaft to bend or twist as it would require human effort to compensate for this and the golfer already has enough moving parts. Shaft flex is a marketing tool to hike prices of what should be a cheap to buy item and I am yet to see manufacturers robot test compare their shafts with a competitor. If shaft flex makes a difference why are there no options for carpenters hammers?
Robert,
“Shaft flex is a marketing tool”? Wow. Double wow for the hammer analogy. When was the last time a carpenter tried to swing a hammer 120 MPH?
-Matt
Was this a blind test, meaning did the players know the flex of the shaft on each shot? My second question is, does shaft flex actually matter on shorter irons? If this same test was done with 9 iron or wedge, would there still be a statistically significant difference?
Jeff,
Players were able to look at the shaft, but we didn’t tell them what we handed them.
Shafts matter in all clubs. The differences will be smaller in more lofted clubs, but the expectation for precision is higher, too.
-Matt
As a twenty year veteran of the golf shaft industry I can say with complete confidence that if “puring” shafts improved performance the USGA would make it illegal.
Thanks! I know I’ll be re-evaluating the things I’ve seen with my own eyes based on an anonymous post. /sarcasm
-Matt