Grouchy Golf Blog

Sunday, October 15, 2006 at 11:16 PM

Correct Shaft Flex: Stiff or Regular? Can You Handle the Truth?

One of the biggest equipment faux pas that golfers make is playing with golf shafts that are too stiff for their swing. Most of this can be directly traced to the golfer's ego. Just like there are no men driving VW Beetles with those dainty flower holders, the macho factor won't allow male golfers to play anything less than a stiff flex.

However, it is important to understand just how shaft flexibility affects performance. After all, the shaft is often known as the "engine" of the golf club.

Theodore P. Jorgensen authored a book called "The Physics of Golf." He conducted several experiments to demonstrate that the shaft of the golf club during the golf swing actually bends forward at impact. Jorgensen provides a graph indicating that the clubhead lags behind the hands at the start of the downswing. However, by the time that the club is about horizontal to the ground, the clubhead catches up to the hands and eventually leads the shaft at impact.

This is counterintuitive to what most people believe. While all golfers acknowledge that the clubhead lags at the start of the downswing, most assume that it continues to lag until well after impact. Furthermore, it is commonly assumed that the more flexible the shaft, the more that the clubhead lags throughout the swing. Golfers assume these things because that's what it feels like during the swing. However, as with many things in golf, what you feel is not always what is real.

In reality, the shaft unloads during the downswing and kicks forward by impact, regardless of swing speed or shaft flex rating. Our hands simply cannot outpace the clubhead as the shaft unloads during the golf swing. In fact, the more flexible the shaft, the more that the clubhead will kick forward, increasing velocity and effective loft. Therefore, all other things being equal, softer shafts provide more distance and a higher trajectory than their stiffer siblings. This applies to all human-generated swing speeds, including that of Tiger Woods. Tiger himself acknowledges this phenomenon writing, "If I had weaker shafts I'd hit the ball farther just because there's more flex in the shaft and more kick in a regular-flex shaft than in the stiff shafts I use."

So why doesn't Tiger switch to "senior" flex shafts? While a more flexible shaft will provide more distance, the tradeoff is less control. It is simply much more difficult to control the clubface at impact with a more flexible shaft. The last thing that Tiger wants to do is to miss more fairways! For the rest of us, distance is probably our primary concern. Regardless, it is very important for us to play with the right flex for our unique swings. If you haven't done so already, I recommend that you visit your local golf retailer and receive a proper fitting. Finding the correct flex is fast, easy, and usually free.


Anonymous Anonymous said...

Good Morning Grouch.

Thanks for the physics reference. I "see" the physics in my head, but have no physics background. Great column.

You rock.



Anonymous Anonymous said...

well said...flex is a tad more complicated...have you read SEARCHING FOR THE PERFECT GOLF CLUB, by Tom Wishon?

I play clubs which are too stiff for my age, handicap & swing speed.

But I have battled a hook my entire life, hit the ball high, and am more concerned with control than distance....Robert  


Anonymous JimmyJ said...

Hey Grouch - You got some great clubs in your bag. We all know how expensive good clubs are getting these days so sometime just for fun give us the "retail" cost for the 14 in your bag.  


Blogger Golf Grouch said...


Thanks for your comments. I imagine that the total retail price for all of the clubs in my bag to exceed $2,000 if new. However, I bought many of them used and through eBay. Still, they'd probably fetch close to $1,000 if I were to hawk 'em on eBay.

I guess it explains why golf club theft is so widespread these days...  


Anonymous Anonymous said...


i watched some video on youtube.com, n it was sayin how because there are no manufacturing standards as to ho much flex counds as regular, stiff, etc, that some clubs with the same flex shaft can have large differences.

there is an example, they show a test on two clubs with regular flex, one ping and one aldila, and the aldila was a stiff flex whilst the ping shaft was a ladies or senior flex - seems scary!

i use stiff shafts cos i'm a big hitter (just a shame i have the touch of an elephant around the greens). i had my clubs fitted, i'd recomend it to everyone, its usually free if you buy a club.  


Anonymous Anonymous said...

Thanks for the information...tried a few different 3 woods the other day and although I have a Taylormade driver stiff shaft in the bag, the 3 wood that I tried worked better in regular flex. Your article made up my mind; i'll include the regular shaft 3 wood.


Anonymous Anonymous said...

Great article, until you got to the part about more flex causing increased velocity of the clubhead (assuming, at exact moment of impact!) Fact is, there is no difference in clubhead speed at all at impact whether flexible or not. Though counterintuitive, the only effect of differing flexes is in feel and ball flight, not increased speed or "kick".  


Anonymous Doug Hufnagle said...

Riddle me this....If the golfer is swinging the club such that the club is accelerating through impact, how in the world is the shaft kicking back. Acceleration means that more and more force is being loaded on the club shaft, and therefore the shaft cannot possibly kick back. HOWEVER, if the golfer has released early, the club will not be accelerating, and then, and only then would it be possible for the shaft to kick back. I firmly believe that the only way to select the proper shaft flex is by actually swinging the clubs.  


Anonymous Anonymous said...

@Doug Hufnagle

I understand your logic Doug, but you couldn't be more incorrect. When you factor in the weight of the club head and the impact to the shaft caused by inertia due to club head weight. Basic physics will prove that the more flex the quicker inertia will straighten out the shaft after the initial flex caused by the down swing. If you took a rope with a weight on it and swung it like a club, by time it was half way round it would have extended out fully with no lag due to inertia. Do the same with a long piece of flat iron with a weighted tip and you would see the iron still flexed through the swing as there would need to be more speed to counter the stiffness and allow the laws of inertia to straighten the flat iron. This is what happens with a club shaft.
The more flex - the less speed is required for inertia to straighten the shaft which also increases club head speed causing a whip. The more stiff, the more difficult it is for inertia to straighten out the shaft due to less initial flex on the down swing)resulting in more speed being required to create (increasing flex)the whip. Due to the whip and the increased club head speed, the shaft will actually flex forward on the front swing as the club head is whipped faster than your swing. Just like with the rope and weight, if you swung it like a club it would lag, then straighten then flip forward as you slowed.
The trick is - determining the best stiffness for your swing speed to create a whip that squares your club head at contact with the ball.  


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