Wishon: “What shaft flex should I use?” By Tom Wishon
Let’s start our discussion by making one thing clear. There’s a lot to fitting the flex and bend profile of shafts — enough to write a whole book.
In asking me to write about the fitting of each of the key specs of golf clubs, GolfWRX in essence gives me a “1-pound bag” each week to offer information about each fitting spec. Covering everything about shaft flex and bend profile would be like trying to put 100 pounds of stuff into that 1-pound bag!
For those who are really into knowing as much as possible about flex and bend profile fitting in shafts, I recommend you read the three-part series I wrote for GolfWRX some time ago.
For those who may not be that familiar with fitting for FLEX and for BEND PROFILE, fitting for the flex is a matter of finding a shaft with the correct swing speed rating for the golfer’s clubhead speed AND transition/tempo, while fitting the bend profile involves matching the tip stiffness design of the shaft to the golfer’s point of release.
Of all the points that an experienced club fitter has to evaluate to do a good job in the fitting of flex and bend profile, the most important one is to have accurate shaft bend profile measurement and swing speed rating data on the largest possible population of shaft models and flexes. This is because there are no standards for the flex of a shaft in the golf industry. Each golf company and shaft company is free to decide how stiff any of their letter flex codes on their shafts are to be. As such, the R flex from one company can be of the same stiffness as the S flex from another company or the A flex from a third.
Without access to a large data base of actual stiffness and swing speed rating measurements for shafts to be able to clearly know and compare the stiffness design of shafts, fitting for flex and bend profile is a matter of time consuming and frustrating trial and error. Period.
The following bend profile data graph is simply offered as an example of the type of shaft stiffness measurement data required to take shaft flex/bend profile fitting from a trial-and-error process to one of clear, succinct organization. This example graph will also prove the point about the confusion in flex due to a lack of standards in the industry.
Each of the five shafts in this graph are labeled and sold as S-flex shafts. The stiffness measurements represent a range of three full flexes, or stated another way, represent a swing speed rating difference of more than 30 mph.
With such data, the flex and bend profile fitting analysis follows these procedures:
1. Accurately measure the average clubhead speed of the golfer with a driver and a 5- or 6-iron.
2. Observe the golfer’s downswing transition and tempo and evaluate it as either:
A) Smooth/gradual/passive with little sense of acceleration.
B) Average, with some sense of force and acceleration from the transition through the downswing.
C) Forceful and aggressive, as if the golfer cannot wait to pour on the coals to accelerate the club to impact.
In simple terms, the club fitter is observing whether the golfer is more of a swinger (A), a definite hitter (C) or somewhere in between (B) with his downswing transition and tempo.
3. Observe the golfer’s point of release (i.e. the point at which the golfer begins to unhinge the wrist-cock angle on the downswing as either (1) early, (2) midway, (3) later, or (4) very late. Another way to evaluate this is to reference the point of starting the release to the hour numbers on a clock while facing the golfer.
(1) Early: 11 to 9:30
(2) Midway: 9:30 to 8:30
(3 Later: 8:30 to 7:30
(4) Very Late: 7:30 to 6:30
4. Choose shafts of the correct weight (see my story on shaft weight/total weight), which have a swing speed rating that matches to the golfer’s clubhead speed and an adjustment for their transition and tempo evaluation with a tip stiffness design that matches the golfer’s point of release.
We will use an example of a golfer with a 100 mph driver clubhead speed. The up or down adjustment in the swing speed rating and tip stiffness recommendation is the same for all other clubhead speeds.
The above procedures are done to give the club fitter A STARTING POINT for shaft flex and bend profile fitting. Suitable candidate shafts are chosen by the club fitter from which the test club hitting process begins.
Again, because the best club fitters are superb multi-taskers during the test club sessions for flex and bend profile, the club fitter is also testing for shaft weight, swing weight and continually asking the golfer for feedback with each change of head weight or shaft.
Without question, the matter of ADVANCED PLAYER SHAFT FLEX/BEND PROFILE FITTING must also include an evaluation of the golfer’s preference for feel elements and shot shape/performance related to the flex/bend profile. Experienced club fitters will ask the golfer to provide the names of shafts the golfer has used, along with the golfer’s feedback of too high, too low, good flight, too stiff feeling, too flexible feeling, just right feeling, etc.
With this information, the club fitter will access his database of shaft stiffness measurements to study as many of the golfer’s previous shafts and compare the stiffness measurements. Through this process, the club fitter will be able to know what the actual stiffness measurements are for each shaft model feedback opinion from the golfer. From this the club fitter will have a very clear picture of what the stiffness measurements need to be to best satisfy the golfer’s feel and shot shape preferences.
Again, with the right database of shaft stiffness measurements, the process of flex and bend profile fitting becomes a very organized, very orderly, and very accurate process. Without such information, shaft flex and bend profile fitting will forever be a matter of trial and error.