Understanding Shaft Geometry and the Effects on Ball Flight

Key Golf Shaft Variables To Learn When Shopping For Your Next Set of Clubs or Re-Shaft Project

Following our back-to-school theme, last week I spoke about how the geometric shape of your putter grip could improve you putting.  Today, we are going to switch to golf shafts and show you a few things to look for when looking to re-shaft or purchase your next set of clubs.

Did you ever wonder why certain golf shafts hit the ball higher or to the left or right more than others? This has to do with a number of parameters, one of which is the shape or geometry of the shaft.  Let’s take for example parallel tip steel iron shafts. The majority of men’s flex parallel tip steel iron shafts have a tip diameter of 0.370” so they can fit into numerous heads across the industry and a butt diameter of 0.600” to accommodate the majority of golf grips.  The geometry between these areas is what alters the ball flight.

Golf Shaft AnatomyIf you look at steel iron shafts, each model has its’ own unique step pattern.  The stepping is done to change diameters or the rate of taper and ultimately the geometry of the shaft.  The same thing occurs on non-stepped shafts as well; the shaft becomes larger in diameter from the tip to the butt end.

Download Hireko CatalogThe step pattern may be constant, like the True Temper TT Lite with consistent 1.5” steps or an FST 115 with 1” steps.  The shaft might have variable steps such as an Apollo Shadow with 9 small ½” steps and then increasingly larger steps as you go toward the butt end. The stepping helps to identify a model.

Why does a more flexible shaft hit the ball higher in the same pattern of shaft?  This goes back to geometry as the step pattern will be the same, but the more flexible shaft will have a longer parallel tip section and shorter parallel butt section. Since the shaft is skinnier near the tip, it will allow the shaft the bend further forward prior to impact creating more dynamic loft and/or a more closed face. Conversely, if you want to stiffen a parallel tip shaft, you do so by taking more off of the tip and that will resist the forward bending.

Less than a year ago, we added a piece of equipment to help us measure shafts more precisely.  We have measured quite a few shafts already. Two of which are the Apollo Acculite 85 S-flex and a True Temper Dynalite Gold SL S-flex.  These might not be common shafts that our readers have had an opportunity to hit, but both are listed a high launching by the respectively manufacturers, had nearly the identical final frequency for a 5-iron and they are pretty close in cut weight (Acculite 85 at 87.3g and Dynalite Gold SL at 93.1g).  On paper these would appear to be similar.

Our shaft profiler measures the deflection or stiffness along the length of the shaft so you get more of a complete picture.  The following chart shows the deflection of the two shafts with the left side showing the tip end and the right side is the butt. More flex is indicated when the line is higher on the chart.

Tip Stiffness

From about 14” up from the tip to the butt end, these two shafts are nearly identical. Where you can see the main difference is tip section as the Dynalite Gold SL being much stiffer.  This is due to the fact that the shaft tapers quickly.  Instead of the entire parallel tip section remaining 0.370” up to the first step, both of these shafts has a tapered section before the first step to give them stability.  Just underneath the 1st step the Acculite 85 is 0.400”, but the Dynalite Gold SL is a whopping 0.445” below the first step!

That explains the difference as the larger cross section or shaft diameter, the stiffer the shaft becomes.  I shafted these up into identical heads and head to the range for me and others to hit as we could look at the effect on ball flight when one area of the shaft is decidedly different.  What we witnessed was the Acculite 85 would hit the ball more to the left than the Dynalite Gold SL (we were all right handed).  For those that fade or push the ball would prefer the Acculite 85 as the softer tip will help close the face at impact.  For those that pull or draw will prefer the Dynalite Gold SL. Or is it simple as that?

The reason I bring this question up has to do with clubhead selection.  While we saw a definite change in ball flight between the two shafts in the same head, we could have placed the Dynalite Gold SL in a head with more offset and the Acculite 85 in a model with less offset and you might hit the ball the same direction and height.  Just as easily, we could have had placed the Acculite 85 in a high offset head and created a draw or hook and the Dynalite Gold SL in a low offset head and produced a fade or slice.

Remember that a club is a system consisting of the head, shaft, grip and length. This is where fitting is extremely important and how our QuikFit system can help identify combinations of heads and shafts that will work harmoniously with a given player’s swing.  But now you may look at the shaft geometry in a different perspective and understand better why you may like or not like a certain shaft or why.

SK Fiber Wraith Golf Shaft


  1. Bill Gibson says:

    Great article on steel shafts. Any insight on the carbon fiber shafts, especially how to tell the difference between them?

  2. Keith Luhnow says:

    Really a well done article . Can’t say I’ll ever build a club ,but I really love the game and enjoy trying to improve . I’m a little long in the tooth [73] ,and have gotten shorter with most of my clubs ,but i believe almost all the golf club makers have been working on getting more distance out of their irons ..so i’m looking at new irons and would appreciate input .. Mizuno,Callaway ,Ping .. My Callaway irons have a senior graphite shaft .In your opinion are the graphites better then the steel or are they pretty close in performance .. IRONS . THANKS KEITH

  3. Gene W Wines says:

    Jeff: I really enjoyed this article. As the shafts in the inventories are getting so many, a old timer like me gets a little confused. After reading this article, above. Made me feel a whole lot better in Shaft Sections for my players, fitings.

    I just find the TT-Lite, and the Dynalite SL, hard to beat. What I really like about these two safts, was the frequency response after assembly, You can take the club had, Hold the shaft real lightly, and let the club hand down about your chin..YOU will feel the the frequencies, in your thumb and trigger finger, they are obviously frequency tones coming up the shaft from the Center of the Club Face…that feeling is balanced club, play’s really good too. –30–

  4. Jeff Summitt says:


    Composite shafts are a little different because you have multiple materials and angles to consider versus a steel shaft which is made of a homogeneous material throughout. Geometry still plays an important role to control stiffness (parallel tip and butt sections) along the lines of the shaft, but material changes can completely transform shafts.

    A good source of information on the various graphite shafts can be found in our annual Shaft Fitting Addendum.

  5. Jeff Summitt says:


    You can find very good quality graphite shafts for irons that are just as consistent as steel. Granted the price will be higher, but graphite shafts have much more freedom of design over steel. The key is the fit for the weight as well as their flex and flight trajectory.

  6. Phil king says:

    Looking for an answer to shaft fitting . I have read meany articles on shaft flighting , and I can see it’s not all that easy. What I want to do is put a nspro 950 gh shaft in my wedges i’am thinking to make them stiff but not wedge stiffness , I wood like to still have some feeling in them. I have shafts out of a 6 & 7 iron in shift ,witch end should I cut to get about a stiff and how much to cut. I’am thinking if I cut it all off the head end it will be to stiff again. Hope some one can help me with problem. Thanks Phil

  7. Jeff Summitt says:


    If they are taper tip, then you won’t be able to tip trim and put them back into a taper tipped head without reboring the hosel.

  8. Phil king says:

    No Jeff they are parallel tipped shafts so are the wedges their going in so I can trim both ends. I know a softer tip will give me a higher ball flight witch I want for my wedges but not to soft a shaft for digging the ball out of the rough around the green. ????

  9. Jeff Summitt says:


    For the 6-iron, you may have to tip trim an extra 1.5″ to create the flex for a wedge and an extra 1″ for the 7-iron. I might be hesitant to cut all off the tip without knowing if there was a big variance in the bottom of bore to ground line measurements.

  10. Phil says:

    I have a titliest d2 driver with a graphite design ad d1 s6 shaft . My swing speed is 105 and very smooth. I hit it straight but very high. I’am thinking to shorting the shaft cutting the but end a little should stiffen it and bring down ball flight and get more distance. I’am older guy but in good shape. What suggestions do you have. Can I just choke up and get the same results..???

  11. Jeff Summitt says:


    I would highly suggest choking down first to simulate the effect of a shorter club length. You will find out quickly if that has any affect on reducing your ball flight. If it does, look closely at the impacts on the face because they may start to be lower than the center of the face and create distance loss.

  12. Phil says:

    Torque ??? I seem to only hit a shaft with a torque above 3.0 and up . Don’t quite understand what the torque is and what it does in the shaft and how height or low I should hit . Swing speed a little over 100. Hope you can explain this to me , thanks phil

  13. Jeff Summitt says:


    Shaft torque is a very confusing parameter because it is hard to quantify it by itself. The only shafts made that are virtually the same with the only change being torque are the UST VTS shafts. By hitting these (low, mid and high torque) in the same weight and stiffness classification would you truly know that low torque or a number of other factors is what causing you not to like low torque shafts.

    With that being said, most shafts that are low torque are generally very tip stiff and that might be the root of the cause more so than the torque itself.

    To understand a little more of what torque is, here is a video:

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