Engineered Golf

Shaft Fitting

Shaft Fitting at Engineered Golf

The craft of shaft fitting is complex; it's science, art and technology all wrapped up into one package.  No other component of the golf club is as closely tied your swing mechanics.  Identical shafts that you and your buddy have will perform differently for each of you.  You might get less launch angle and describe the feel differently than your friend.  This is a critical point in shaft fitting.  Engineered Golf's club fitters are able to recognize the movements of the golf swing that have a definite effect on shaft performance.  We can accurately fit the golf shaft for you.

 

There are three primary swing characteristics that have the most effect on the performance of the shaft.

  1. Backswing to Downswing Transition
  2. Downswing Tempo
  3. Wrist-Cock Release
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TRANSITION
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TEMPO
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RELEASE

To be able to accurately fit you with the best shaft for performance, and feel, we're able to not only identify these swing characteristics, but also identify variations within each.

Our shaft fitting procedure also incorporates observing your swing for some sub-characteristics in the selection of the best shaft.

  • We assess your your initial swing speed versus a shaft swing speed rating.
  • Then we identify your transition move to determine the final swing speed rating of the shaft.
  • Combined with the swing moves we mentioned earlier, we'll determine your optimum shaft's bend profile design.
  • We also throw in a little common sense in the selection of shaft weight and torque resistance.

Now you have the basic premise of real common sense shaft fitting that's done at Engineered Golf.

Don't get caught up in the principle that shaft flex stiffness leads to hooks or slices. Stiffness is a closely related characteristic of the club weight. The correct weight and length for each individual are the main keys to accuracy and dispersion.  When we combine that with center face contact we also improve distance.  We're humans, not robots, so we can't clamp the butt end like Iron Byron. We react much more to weight, length and balance point of the club than to flex. Most think of flex in just the butt section when the flex profile of the whole shaft is the proper descriptor of the shaft's characteristics.

Eighty percent of golfers will be substantially influenced by the total weight of the shaft, and then the balance point of the club. Generally, stiffer flexes weigh more and promote a more inside to out path. Why? Try swinging a heavy sledge hammer. You'll find it easier to swing inside on a flatter motion. You're not fighting gravity as much as trying to lift the weight more vertically on a steeper plane.

 

Move into a stiffer flex and it results in a heavier total club weight.  That heavier total club weight promotes a more inside to outside path. The inside to outside path puts draw spin on the ball. Next, by varying the weight of the clubhead, you will see the club head weight influence the face-to-path relationship that is the key to the initial direction of the golf ball. Increase the headweight and less club head rotation occurs, less headweight and more rotation. The initial ball direction is due to 85% club face orientation, 15% swing path.

Get the total club weight and the proper headweight correctly matched and you will see the ball start initially out to the push side but recover down the line under the influence of the draw spin and return to the target line. The path of the swing contributes most to the spin axis of the ball. The face angle relative to path contributes about 85% of the initial direction the ball starts on.

The swing plane will also get flatter with length from wedges to driver. The reason - the increased length is harder to swing/control due to higher total MOI. It feels heavier. Inertia combines the effect of mass plus distance squared. We benefit when the total mass decreases from wedges to driver. But this weight drop is far, far exceeded by the negative affect of increasing length.

When we talk about the whip effect of the shaft during the swing, we concentrate on the tip section. Very high speed photography, (40,000 fps), with the Phantom camera model limits the individual screen capture problems and shows that the shaft can have a forward bend before impact.  The shaft bends forward because the clubhead's C of G is actually behind the shaft's axis.  The C of G tries to re-align itself with the shaft axis when swung.

 

Imagine swinging a stone on the end of a string. The stone's mass is aligned with the axis of the string.  The club head and shaft also act like the string and stone, with some modifications. The shaft is a fairly rigid body when at rest, or not accelerating too quickly. It bends and deflects under force. The inertia of the club head resists movement when we start to swing the club. When in motion an object wants to stay in motion. We swing the club and accelerate it on the downswing. However, the club head lags due to inertia.

When the wrist cock is released during the downswing we see a final spurt of club head speed. Then the hand speed slows down because we've used up that bit of radial acceleration; but the club head wants to remain in motion. It's now that the C of G of the head tries to realign with the shaft axis, and you see a curving of the tip of the shaft. More speed, more forward shaft bend.

shaft fitting
REPRINTED FROM TOM WISHON'S COMMON SENSE CLUBFITTING BOOK

Get the timing right and you see that realignment occur at impact. Release early and that forward spring-like affect of the head's C of G falls back into it's static position in advance of impact.

Woods have a deeper C of G from the face of the club than irons. That helps to explain the re-positioning of the C of G during the swing is more dramatic for woods than irons. Another reason that the woods kick more forward than irons is due to the shaft length. The shorter shafts just do not deflect as much. They do not droop as much. They also do not twist as much.

Shaft butt flex does not necessarily affect ball direction. Each person is different. Common sense shaft fitting at Engineered Golf will reveal your best solution based on your swing.  Contact Us to arrange your fitting.

Engineered Golf