Are You Playing The Wrong Flex?

Read this before you get fit!

Why? First of all the majority of golfers still have never been fit for a single club in their bags…and for those that have we estimate that over 50% of you still are not playing the correct shaft flex.  And if you include further fine tuning (which you should) to the in between flexes…well over 80% of golfers are not fit with the right flex.  Whether you go to a high end fitter or your local big box, one of the most important decisions you will ever make about your new clubs is picking the proper shaft flex.  Want to make sure you pick the right one?  Read this shocking data in our latest “MyGolfSpy Labs” series.

Three shafts that will help you decide which to use, stiff or regular flex

What do you know about shaft flex?

I’d guess that most of you would have heard some of the following bits of “common knowledge” and or myths regarding shaft flex:

  • I hit the ball ____ far therefore I should play a stiff flex.
  • faster swing speeds equal stiffer shafts
  • slower swing speeds equal weaker shafts
  • A softer flex gives you more “kick” and ballspeed
  • A stronger flex makes the ball fly straighter
  • whippy shafts make you slice the ball
  • You should play the softest shaft you can control OR You should play the stiffest shaft you can get airborne
  • Stiffer shafts are “anti-left” and softer shafts are “hook machines”

Well, friends, you can trust that where there is  “common knowledge,” you can find me close behind to either validate the “wisdom” with data or burn it to the ground.  Today I’m taking on the topic of shaft flex. A highly under-rated aspect of the fitting process.

Shaft flex is probably the most common component of club fitting.  Even those golfers who eschew the benefits of a more complete fitting usually want the right flex in their shaft.  But what is the right flex?  How do you find it?  What are the benefits?  And what are the problems with playing the wrong flex?  We’re here to help you find those answers.

MGS Labs: Shaft Flex


For this test, we had three golfers test drivers with regular, stiff, and extra stiff shafts.  Every player used the exact same head: a 10.5* Callaway RAZR Fit.  To keep the testers from knowing what shaft they were testing, UST Mamiya supplied blacked out shafts with no distinguishing marks (I marked the grips so that I would know which shaft was which). The shafts were the same weight, torque, and bend profile, the only difference was flex.

Each golfer hit 10 shots with each shaft and the results were measured by our FlightScope X2 launch monitor.  All testing was done at the range at The Bridges of Poplar Creek Country Club.

A golf club that will help you decide which to use, stiff or regular flex


The results of our test group spit directly in the face of conventional wisdom: THERE WAS NOT ONE CONSISTENT TREND.  Even the shaft manufacturers, give you guidelines such as “Stiff flex fits 90-100 MPH,” clubhead speed is only a starting point If we had fit our testers only based on clubhead speed, our highest swingspeed player would have lost 9 MPH of ball speed!

Now, before you run to the comment section and say that three testers is not a big enough sample size, please read the next paragraph:

As I compiled these results, I was shocked by what I saw.  I immediately fired off an email to UST Mamiya to see if their findings (they have done this same exact test with hundreds of golfers) were equally chaotic.  They assured me that they were.  Sometimes a slower swinger needs an X-flex.  Sometimes a big hitter needs a mere stiff.  It’s all about fitting the individual and there are no hard and fast rules.

A chart that will help you decide which to use, stiff or regular flex

Three golf club handles that will help you decide which to use, stiff or regular flex


So, how did our “common knowledge” hold up?

  • A softer flex did not equate to more ballspeed
  • A stronger flex did not universally create straighter shots
  • For 2/3 testers, the stiffer shafts did minimize the amount of “left” in their shots.

So, if we’re generous, “common knowledge” went 1 for 3.  Not bad if we’re playing baseball, but not very good when we’re talking about a new club purchase that can easily eclipse $300.

There are two things you should keep in mind when buying your next driver (or any club):

1) Shaft flex is a very important variable in fitting.  Our testers saw variations of as much as 22 yards of distance from one flex to another. Getting the right flex is key to an optimal fit.

2) “Fitting” by guesswork and common knowledge does not work.  Period.  You need to get fit by a trained professional.  Let me go a step further: you need to hit the exact combination you’re thinking of buying because you never know what it will do until you hit it.  Keep our big hitter in mind: with his 110+ MPH swing, “common sense” would have given him the X flex…at a cost of 9 MPH of ball speed and 22 yards.

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(MYGOLFSPY LABS) Powered By: FlightScope X2

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