Ah flex…..

It’s one of the most basic, for sure the most talked about and yet still the most misunderstood golf club attribute there is. In fact, most golfers have no idea what shaft flex they’re even playing.

I know, it says it right on the shaft.

I ‘m aware that every manufacturer marks each shaft with a flex designation, whether it’s regular, stiff, extra stiff or some numeric labeling system. What I am telling you is these are practically useless.

You see, there is no industry standard for flex. Nothing. No agreed upon guidelines, measured values or even method of measurement. Nada.

While consumers walk around thinking a True Temper stiff is the same as a Callaway stiff or a KBS stiff, the truth is they’re not. Because of a lack of universal standards, the flex designations on all golf shafts are truly arbitrary. They can’t be used in any way to compare the relative stiffness of one model shaft to another. They can only tell us how stiff a shaft is in relation to the other flexes of the exact same make and model. A KBS Tour extra stiff is stiffer than a KBS Tour stiff which is in turn stiffer than a KBS Tour regular. These markings don’t tell us a KBS Tour stiff is the same as a Dynamic Gold S300.

Yup. It’s true. All those stiff shafts you’ve been buying for your whole have l all been different flexes. These differences range from the subtle to the extreme.  In fact, what’s marked as a stiff flex in one make and model often corresponds to a regular or extra stiff in another. Even shafts from the same manufacturer with identical markings can be different.

Shafts models designed for the professional tours typically play stiffer to their markings than the like marked shafts designed for the consumer market. On top of that, as younger generations of golfers have grown bigger and stronger, many manufacturers have responded by making their shafts stiffer and stiffer without changing the markings.

As you might imagine, this is a serious problem for consumers and club fitters alike. How can you have a great fitting if the fitter doesn’t even know what flex they’re handing you? What’s billed as a fitting can quickly degrade into a try and buy scenario. Golfers only have so many good swings before fatigue sets in, we don’t want to waste swings on shafts that are wrong from the start.

To avoid this and improve our fitting results, here at Total Fit we measure every shaft in our fitting matrix for its true playing flex using our Auditor 50416 Shaft Analyzer. We also use the Auditor to take segment measurements and establish the shaft profile for each shaft. Shaft Profile is the distribution of flex throughout the entire shaft.  We’ll discuss more about that in upcoming posts but for now let’s keep the discussion to overall flex. But what is flex? Let’s define it.

Flex is a shafts resistance to bending or ability to bend when a force is applied. Either way you look at it it’s the same thing so we can measure it two ways. We can apply a force to our shaft and measure how far the shaft deflects like an old-fashioned deflection board does, or we can deflect a shaft a specified amount and measure the pressure exerted by each shaft. This second method is what we use for our Total Fit equalized flex ratings.

To create our database, we measure each shaft’s resistance to bending in ounces when deflected 3 centimeters. This gives us the relative stiffness of each shaft to the others but still doesn’t answer the question of which value range we call stiff? Which should we choose for regular? One could argue that it doesn’t matter as long as we know the relative Flex of each shaft. Although that’s true, we find it helpful to classify things to make communication with our clients easier.

At Total Fit we use the average measurement of every like marked shaft in our matrix to establish a median rating. From this median rating we create a flex range.  So our stiff range is based on the average of all the stiff shafts in our matrix. Our regular range is based on the average of all of the regular shafts in our matrix. Because these ranges are based on averages, there are shafts which are marked as one flex from the factory but fall into a different flex category when equalized.  There are regulars which play stiff and stiffs which play regular.

Ok, so once we’ve established the true flex of our shafts, the question turns to which flex is best for each golfer?

In an attempt to simplify a decision which is anything but simple, the industry decided some time ago to focus on club head speed as the designator of flex. This one simple mistake has hurt millions of golfers for decades.

I’ll tell you why in another installment but please stop picking shafts by swing speed!

At Total Fit, once we establish the proper flex rating for each client, we can easily target other shaft makes and profiles in the same flex range or make targeted selections to increase or decrease the flex rating for a particular player. These manipulations can be used to improve accuracy or even increase distance. We’ll discuss the particulars of how we do this in future posts.

Before I wrap it up, I’d I like to address one more common industry misconception when it comes to measuring for flex. Many people think that you can measure flex with a frequency machine. I won’t go into a full explanation of what frequency machines are, but they measure how many cycles per minute (or CPM) a shaft oscillates when clamped into a vise and vibrated. You can read more about how they work here. We love them and use them every day and while frequency machines do take measurements related to flex, using them to determine overall flex is a mistake. Don’t do it.

I hope this gives you some new insight on shaft flex and how important it is to look past the factory markings when comparing products. It’s ideal to get fit by an outfit which measures for true flex like we do here at Total Fit, but if you are trying clubs on your own, don’t get caught up with the markings. If a shaft feels stiffer to you, it likely is regardless of markings. If it feels softer that’s likely true as well. To really optimize your distance and accuracy, don’t limit yourself to misguided swing speed recommendations, gender assumptions or ego and hit the flex that goes the farthest and straightest!