The amount a golf shaft bends during the swing is referred to as “flex.” No other element of a golf club is as important as the golf shaft flex. Why? Because the position of the clubhead shifts during the backswing and again in the downswing depending on the flex of the shaft. If the club bends too much it makes it that much harder to return the clubhead squarely to the ball and produce well-struck golf shots.
The flex in a golf shaft will impact the accuracy, trajectory and distance of every shot you play. There is a saying around golf that the shaft is the engine of the golf club. Another way of thinking about golf shaft flex is that it is the horsepower in your car’s engine. The only way to maximize the performance of your golf clubs is by harnessing the power of the flex in your shafts.
As a general rule of thumb the faster the swing, the more the club flexes. Golfers who generate clubhead speeds over 100 miles per hour will require stiffer shafts to minimize the flexing of the club and golfers who favor a smooth tempo will benefit from clubs with more bend in the shaft. Observing your normal ball flight can go a long way to determining the proper golf shaft flex – shafts that flex too much whip the clubhead back to the ball too quickly resulting in pulled shots while shafts that do not flex enough tend to deliver the clubhead late to the ball and hang shots out to the right (for right-handed golfers).
There are no industry standards to measure golf shaft flex so the amount of flex in golf shafts varies from one manufacturer to the next. The only way to find the ideal shaft flex for your game is for a professional fitter to watch your ball flight and take measurements with a launch monitor. Each golf shaft bends at a point somewhere along the golf swing, storing up energy in the process. When the club straightens the energy is released and club head speed is increased. In golf lingo this is loading and unloading the club. Finding the ideal flex point for your golf swing is called the bend profile and determines how a custom-fitted shaft will be constructed to put more horsepower in your swing.