Shifting a portion of the clubshaft’s mass distally: does it improve performance?

Abstract

The purpose of this paper was to examine the claim, based on a pendular swing demonstration, that moving a portion of the mass from the grip end of a golf club to a position further down the clubshaft improves clubhead speed at impact. A twodimensional model of a golf club was used to simulate the pendulum swing demonstration provided by a company that purportedly showed that such an optimal shifting of the club’s mass increased the velocity of the clubhead at impact. Two sets of simulation experiments were performed. The first supported the video demonstration provided by the company, which showed that a club’s swing-speed, while swinging under only the influence of gravitational torque, could be increased by relocating a portion of the club’s mass further down the shaft. However, in the second set of experiments when an externally generated torque was applied to the grip end of the club, as would be the case for the uncocking of the wrists during the later stage of the downward swing, the relocation of mass further down the shaft proved to have a detrimental effect on the generation of clubhead speed leading up to impact. Thus, a pendulum swing, which uses only gravitational torque to drive the system, is an inappropriate test for evaluating the benefits of club design modifications intended to improve clubhead speed at impact.