If club fitting variable No. 1 is length and No. 2 is lie angle, then No. 3 is shaft flex. Shaft flex is defined as the relative bending and stiffness of a golf shaft. Flex influences both distance and direction. Shafts were made out of hickory wood from the 1800s until the 1920s when steel was finally allowed by the USGA.
In the golf industry, the terms bend point, kick point, and deflection point are often used interchangeably. However, bend point is really the 1.7-inch area within which the kick point is found. A low kick point produces a high ball flight. A high kick point produces a low ball flight. Deflection point refers to the maximum flex point of the golf shaft.
Shafts have three main performance characteristics: flex, bend point, and weight, and the shaft’s main purpose is to bring the clubhead into proper impact position with a predictable and repeatable swing that creates a balanced follow through. When fitting for shaft flex, a balanced finish position is a key component to look for. A balanced finish is often due to a shaft that fits the golfer. An incomplete finish is often due to a shaft flex that is too stiff. Here are some things to consider when fitting for shaft flex:
* Flex should be determined by the golfer’s clubhead speed, and every golfer’s clubhead speed is different.
* Shaft flex is controlled by the thickness of the shaft wall. The thicker the wall, the stiffer and heavier the shaft.
* Graphite shafts weigh anywhere from 45 to 95 grams.
* Steel shafts weigh anywhere from 104 to 145 grams.
* Shafts do not lose their stiffness over time unless they are damaged.
* Adding one-and-a-half inches to the length of a shaft decreases the flex by one.
Master club fitter Tom Wishon offers an explanation of professional shaft fitting in the following video:
A shaft that is too stiff and therefore too heavy will produce a low and/or push in ball flight. A shaft that is flexible and therefore too light will produce a high and/or pull in ball flight.
The twisting of the shaft during the swing is called torque. High torque means there is a lot of twist, while low torque means there is little twist. Graphite shafts have 2.0-8.0 degrees of torque. Steel shafts have 1.5-6.0 degrees of torque.
Did You Know?
* Shaft stiffness will affect a player’s balance
* 90% of golfers perform better with more flexible shafts
* When a shaft gets shortened, the flex gets stiffer (higher kick)
* When a shaft gets lengthened, the flex gets softer (lower kick)
To compensate for a shaft that is too soft, a golfer will swing off balance and may swing too fast because the shaft is too light. He may also employ a weak grip and aim to the right (if he is right-handed). To compensate for a shaft that is too stiff, a golfer will swing off balance and may hang back because the shaft is too heavy. He may also employ a stronger grip to control his push ball flight.
Shaft Flex Selection Chart
Carry distance under 180 yds/Swing speed under 75 mph = Ladies (L) flex
Carry distance 180-200 yds/Swing speed 75-90 mph = Senior (A) flex
Carry distance 200-240 yds/Swing speed 90-100 mph = Regular (R) flex
Carry distance 240-275 yds/ Swing speed 100-110 mph = Stiff (S) flex
Carry distance over 275 yds/Swing speed over 110 mph = Extra (X) stiff flex