Shaft Flex doesn't matter! - Mark Crossfield

[dkolo]

No, the videos point was that no matter what FLEX you use. They were trying to isolate the importance of FLEX. As they said in the video the primary influence the shaft has is on how if feels to the golfer. You wont be seeing drastic changes in actual numbers.

Now how it feels is based on the Bend Profile, the weighting, the clubhead weight, and how the club loads in the golf swing. Which if you want to say extra stiff is how much it can bend, then yes flex is a very OVERLY SIMPLISTIC way of saying that. Yes you probably wouldn't fit a high swing speed to a very soft bend profile (less stiff shaft). There is probably a correlation between swing speed and certain overall stiffness in bend profiles. Yet there is no significant difference in the actual launch monitor data.

Right, I meant flex specifically, but I got careless in writing there at the end.

[saevel25]

Right, I meant flex specifically, but I got careless in writing there at the end.

No Problem!

[motsco]

I'm not a big numbers guy. I will say that a fitting pro saying flex does not matter is very misleading. there is some very good points in this topic. flex does matter IMHO. no matter what club head you choose you need a flex to match. bend? could be what I call whip? but to have any of that the shaft needs to flex.

[acerimusdux]

Here is Tom Wishon talking about Shaft Flex

Quote:

Shaft Myth #7 – The flex of the shaft has an important effect on shot performance for all golfers

For some golfers, very definitely this is true. But for many golfers, approaching even the majority of golfers, the flex of the shaft is one of the very least important of all the fitting specifications of a golf club.

I think this is the main point Crossfield is missing: "for some golfers, very definitely this is true". And, it's not just due to feel. Tom Wishon is saying that for those golfers whose release causes the shaft flex to still be unloading at impact, "the shaft flex can have a visible effect on the launch angle, height and spin rate of the shaft" .

I think from the other studies cited, it likely is a significant majority of golfers for whom this is not true to any great degree. But there must still be a substantial minority for whom it is tue. All of the people citing their personal experince of this aren't making it up. Maybe some are being decieved by "feel", but certainly some are seeing real performance differences.

[RandallT]

Isn't it possible that Mark Crossfield has a swing with characteristics where flex doesn't matter much. And it's still possible for others to have swings where the flex would matter a lot?

[MS256]

I will say this. My boss (and course owner) is a heck of a golfer and it doesn't seem to matter to him what club he is hitting, or even if it belongs to him. He is going to stripe it right down the middle time after time. As he's out working on the course he frequently sees people he knows getting ready to tee off, borrows a club, and hits a shot right down central with it. I've seen him do it many, many times and I've never seen him mess one up.

[Rip24]

@saevel25 ,

I would still like to see a better study design than Crossfield is presenting.  It should have more data and be a double blind study with a minimum of 10 golfers in each handicap range, (i.e. scratch, single digit, 10 - 19, 20+).  If the golfer knows which shaft he is trying, it can really influence the results.

*********.com did a test in just this way....they tested flex, weight, and torque and found that there is realy no rhyme or reason why one shaft works better than another for a given golfer.  The conventional wisdom about shafts really didnt hold up

http://www.*********.com/*********-labs-wrong-shaft-flex/

http://www.*********.com/driver-shaft-weight-testing/

http://www.*********.com/*********-labs-shaft-torque/

What the hell??  you cant post a link here?   The website that did the testing is My Golf Spy for those interested...

Edit: Oh, I see. They stole a bunch of articles from this site a few years ago so their URL is blocked along with a bunch of spam sites and things.

[boogielicious]

*********.com did a test in just this way....they tested flex, weight, and torque and found that there is realy no rhyme or reason why one shaft works better than another for a given golfer.  The conventional wisdom about shafts really didnt hold up

http://www.*********.com/*********-labs-wrong-shaft-flex/

http://www.*********.com/driver-shaft-weight-testing/

http://www.*********.com/*********-labs-shaft-torque/

What the hell??  you cant post a link here?   The website that did the testing is My Golf Spy for those interested...

Edit: Oh, I see. They stole a bunch of articles from this site a few years ago so their URL is blocked along with a bunch of spam sites and things.

I am not disputing that these tests are not helpful.  I am only asking about the actual test design.  A proper scientific test design eliminates variables that can sway a tester.  If the tester knows which shaft they use, it can affect the way they swing.

Crossfield is comparing shafts that are close in flex (X-stiff vs. stiff).   If we take it to the extreme, X-stiff vs Ladies flex, would there be a difference?  I would assume yes.  So the extremes would show differences. The question then becomes how much difference in flex does there need to be to affect performance.  Only a properly designed test using Design of Experiments methodology and ANOVA testing would provide an accurate result.  It may end up that if you are going from reg to stiff, or still to X-stiff there isn't a difference.

Most magazine and website testing uses quick and easy test methods that are not scientifically validated.

[brookter]

I am not disputing that these tests are not helpful.  I am only asking about the actual test design.  A proper scientific test design eliminates variables that can sway a tester.  If the tester knows which shaft they use, it can affect the way they swing.

Crossfield is comparing shafts that are close in flex (X-stiff vs. stiff).   If we take it to the extreme, X-stiff vs Ladies flex, would there be a difference?  I would assume yes.  So the extremes would show differences. The question then becomes how much difference in flex does there need to be to affect performance.  Only a properly designed test using Design of Experiments methodology and ANOVA testing would provide an accurate result.  It may end up that if you are going from reg to stiff, or still to X-stiff there isn't a difference.

Most magazine and website testing uses quick and easy test methods that are not scientifically validated.

In fact, that's exactly what Crossfield does in the third video -- compares an X with a A shaft (i.e. stiffest to whippiest). There was a difference of 3 yards and 200 rpm, with not a lot of difference in the other numbers either, but the tester hated the A shaft. The discussion is that he's perfectly right in hating it: he feels it's less under control and therefore he won't hit it as well as the X.

https://www.youtube.com/watch?v=N5Z5I8y-uQs

Of course, it's not a scientific test, but it's interesting and they're very clear about the importance of getting fitted (just that flex isn't the most important factor in a fitting), so I don't see it's causing any harm.

[boogielicious]

In fact, that's exactly what Crossfield does in the third video -- compares an X with a A shaft (i.e. stiffest to whippiest). There was a difference of 3 yards and 200 rpm, with not a lot of difference in the other numbers either, but the tester hated the A shaft. The discussion is that he's perfectly right in hating it: he feels it's less under control and therefore he won't hit it as well as the X.

https://www.youtube.com/watch?v=N5Z5I8y-uQs

Of course, it's not a scientific test, but it's interesting and they're very clear about the importance of getting fitted (just that flex isn't the most important factor in a fitting), so I don't see it's causing any harm.

And the tester knew what shaft it was .  That is my point.

[saevel25]

The question then becomes how much difference in flex does there need to be to affect performance.  Only a properly designed test using Design of Experiments methodology and ANOVA testing would provide an accurate result.  It may end up that if you are going from reg to stiff, or still to X-stiff there isn't a difference.

Most magazine and website testing uses quick and easy test methods that are not scientifically validated.

It would be a hard question to answer, cause it depends on shaft design methodology.

If you take Dynamic Golf versus KBS Iron shafts for an example,

You can see with regards to fitting, KBS just removes weight from the shaft to change flex. This is seen in the similar profiles vertically on the left. While True Temper actually changes how the shaft loads with each flex.

I would say if you compare flexes, lets say True Temper's lightest flex to their stiffest, then it could be significant. When you compare KBS, it probably wouldn't change much at all.

This would be the same for graphite shafts as well. Though most graphite shafts have very similar bend profiles with in the same model. Some do the same as True Temper and modify how they load depending on the flex, or might group a few flexes in the same profile.

Now would this dramatically change the launch numbers, it does. I don't know the significance. I would think it matters more with feel than it does with actual hard data. Who's to say that a human isn't modifying their swing to find better contact with regards to how the club feels and loads into impact.

[brookter]

And the tester knew what shaft it was.  That is my point.

Interesting point to speculate though: the numbers are fairly similar for the 2 extremes of shaft -- it's the feel that's different. The tester knows when he's hitting an X and an A shaft, so of course that affects his 'feel'.

But what about the numbers? They are fairly similar -- now either that's a 'clean' result (i.e. unaffected by the tester's knowledge) or it's tainted by his knowledge and this somehow accounts for the similar numbers. If it's the latter, then that implies that the tester can alter his swing (consciously or unconsciously) to achieve similar numbers between the two shafts. Do we think that's possible? (That's a genuine question by the way)

If we don't think it's possible for him to alter his swing to get similar numbers, then that would imply that the tester's knowledge doesn't necessarily have a huge effect on the main purpose of the test ("does shaft flex affect the numbers?").

(Again, I'm not arguing this was a scientific test -- I'm mainly wondering whether a suitably gifted player could change his swing to 'fake' the similarity in numbers. )

[boogielicious]

It would be a hard question to answer, cause it depends on shaft design methodology.

If you take Dynamic Golf versus KBS Iron shafts for an example,

You can see with regards to fitting, KBS just removes weight from the shaft to change flex. This is seen in the similar profiles vertically on the left. While True Temper actually changes how the shaft loads with each flex.

I would say if you compare flexes, lets say True Temper's lightest flex to their stiffest, then it could be significant. When you compare KBS, it probably wouldn't change much at all.

This would be the same for graphite shafts as well. Though most graphite shafts have very similar bend profiles with in the same model. Some do the same as True Temper and modify how they load depending on the flex, or might group a few flexes in the same profile.

Now would this dramatically change the launch numbers, it does. I don't know the significance. I would think it matters more with feel than it does with actual hard data. Who's to say that a human isn't modifying their swing to find better contact with regards to how the club feels and loads into impact.

I think this is why a study would be very complicated.

Interesting point to speculate though: the numbers are fairly similar for the 2 extremes of shaft -- it's the feel that's different. The tester knows when he's hitting an X and an A shaft, so of course that affects his 'feel'.

But what about the numbers? They are fairly similar -- now either that's a 'clean' result (i.e. unaffected by the tester's knowledge) or it's tainted by his knowledge and this somehow accounts for the similar numbers. If it's the latter, then that implies that the tester can alter his swing (consciously or unconsciously) to achieve similar numbers between the two shafts. Do we think that's possible? (That's a genuine question by the way)

If we don't think it's possible for him to alter his swing to get similar numbers, then that would imply that the tester's knowledge doesn't necessarily have a huge effect on the main purpose of the test ("does shaft flex affect the numbers?").

(Again, I'm not arguing this was a scientific test -- I'm mainly wondering whether a suitably gifted player could change his swing to 'fake' the similarity in numbers. )

I agree that with the extremes you can feel the difference.  I believe the shaft companies would counter Crossfield's study with a study of their own showing there is a difference.  I know I can feel a small difference between stiff and regular in the same shaft make.  But between different makers, it is harder.  Swing and overall weight are easier to feel in my opinion.  A proper study would have to at least make the swing weight the same.

[saevel25]

I think this is why a study would be very complicated.

I agree that with the extremes you can feel the difference.  I believe the shaft companies would counter Crossfield's study with a study of their own showing there is a difference.  I know I can feel a small difference between stiff and regular in the same shaft make.  But between different makers, it is harder.  Swing and overall weight are easier to feel in my opinion.  A proper study would have to at least make the swing weight the same.

I know Mark has stated a few times, that Callaway has put all different shafts in their Robot and the numbers differences are similar to what Mark has shown. That the difference in shafts is marginal, and the major issue is the Human Element.

I think in the ********* articles (the ones that were blacklisted above), UST Mamiya provided blacked out shafts, and they had people hit. There was some very loose trends with Torque, Flex, and Weight. Nothing you can hang your hat on, as this type of thing will cause this result. They called UST Mamiya about it, and the shaft company confirmed the same thing with their own studies.

[dwidep]

I had a Callaway fusion ft-3 driver that I played with for years until I bought a rocketballz this year.   Both 9 degrees, but I couldn't hit the new driver straight to save my life.  I have always been a pretty good driver and it was very frustrating to have this horrible slice come out of nowhere.  I went to the range and experimented quite a bit, but I finally was able to solve my problem.  With the fusion, I lined the ball up off of my left heel, but when I did that with my new driver it would always have a ton of left to right.  I started lining the ball up off of the front of my left toe ~4-5 inches in front of my usual, and started drilling the ball.  I tried this with my fusion and pulled everything left.  I played with it this way for about a year, but then decided to get a new shaft for the rocketballz.  With this new shaft I am now able to line the ball up off of my heel instead of having the club face a foot away from the ball at the start of my swing.  I also have a much lower ball flight with the new shaft.  What would be the difference in the two clubs/two shafts besides the shaft flex?

[Rip24]

To play devils advocate for a minute.....and I have listened to a video of Mark stating that he feels like he can adjust his swing to any shaft.    What's interesting (for me at least)...the same website -  who's name can not be mentioned (My Golf Spy) that did the test with the blacked out shafts that showed no real correlation between what may fit a particular golfer the best also did a review of the Motore Speeder line that showed a very definite difference.

The great thing about this review is that they tested the whole Speeder line (5 shafts) not just one shaft like a lot of reviews will do.   And I think the reviewers testing method was pretty solid, not blind but he gathered so much data that I was satisfied there wasn't a bias.   What he found was that from top to bottom carry distance didn't vary much (8 yards)  but total distance was a much different (21 yards between shortest and longest)   Spin and launch also showed significant differences.   And the data very closely matched up with what could be expected from the manufactures spec sheet.

I'm pretty sure Mark's video was only concerned with carry distances so might it be concluded that his results are ignoring the fact that shaft fitting is to optimize launch and spin to achieve the greatest TOTAL distance of carry + roll?

[Rip24]

And the tester knew what shaft it was.  That is my point.

lets not kid ourselves...a person would have to be shockingly oblivious to pick up a A flex and not immediately notice it.

[boogielicious]

lets not kid ourselves...a person would have to be shockingly oblivious to pick up a A flex and not immediately notice it.

Yes, of course.  But can you tell the difference between Project X 5.5 and 6.0?  Or any other shaft in stiff and regular?  Or even the same shaft stepped?  Crossfield argues that flex is not important at all. Yet fitters and golf club manufacturers argue that it does matter.  Unless you set up a blind study with tons of data, the actual effect of shaft on ball flight cannot be determined.