Updated: Aug 30, 2017
By Tom Wishon
Here’s a little fact of life the golf industry never talks about. There are no established standards within the golf equipment industry for shaft flex. Therefore the R flex from one company may have the same stiffness as the S flex from another company, or the A flex from yet some other company. It’s common, it happens all the time, and the result is a lot of golfers walk away from their club buying experience without the right fit for the shafts in their new clubs. Getting custom fit for the right shaft fitting has to consist of four important steps:
1) Swing speeds
The custom fitter needs to measure the driver and 5-iron swing speeds of the golfer. Those measurements must be compared to a full list of swing speed ratings of many different shafts. There are a few companies and clubfitting research sources that take precise measurements of shafts to then be turned into a swing speed rating. Few of the golf club companies that make standard clubs to be sold off the shelf know of or use such reference information. The majority of independent custom clubmakers do.
2) Player strength and shaft weight
The custom fit process will fit the weight of the shaft to the physical strength and aggressiveness of the golfer’s downswing move at the ball. A strong golfer with an aggressive downswing will benefit from a heavier shaft weight (in excess of 85g for woods, and 115g for irons). Whereas a golfer with under average strength and more passive downswing will be much more suited to a very light shaft weight (under 65g for woods, and less than 85g for irons). Golfers with "average" strength and downswing tempo will in general play best with a medium shaft weight.
3) Downswing move
The swing speed doesn't tell the whole story as it may pay to adjust the swing speed rating of the shaft to the intensity of the golfer’s downswing transition move. You might benefit from choosing a shaft with a higher swing speed rating than the actual swing speed measurement, for example, if you have a very aggressive start to the downswing. Conversely very smooth swingers often perform better with shafts with swing speed ratings lower than their actual speed. I think there is a general misconception that longer hitters must use stiffer shafts which is not always true. Swing tempo and transition strength influence correct shaft selection.
4) Timing of golfer's "release"
The club fitter will also take into account the golfer's release - in other words, his unhinging of the wrists before impact. He will try to find an appropriate bend profile design. The bend profile of a shaft is how its stiffness can be distributed over the length of the shaft. For golfers with a very late release (see Mr Hogan, left), shafts with a more tip firm bend profile (the tip end is the smaller end of the shaft) are a better match. Golfers who release the wrist hinge angle early in the downswing (as seen often in weaker hitters) need shafts with more flexibility in the tip design. Players with an in between release should seek a tip medium firm bend profile.
What is the most important element of the shaft for me?
It depends. For golfers with a later wrist hinge release and more aggressive downswing, the more the shaft flex becomes a vital component of performance in the club. The earlier the release and less aggressive the swing tempo, the weight of the shaft becomes far more important for the golfer than the stiffness design for shot performance.