Comparison of clubhead speed of one vs two lever swing.

The various parameters/conditions for the two swings are the same except for the hinge point being either free or not. To be fair, we compare the two swings not at the same time such as for instance t=0.25 but at times when the same kinetic energy is developed. This implies that the work expended by the golfer is the same for both cases.

The kinetic energy at t=0.25 is about 260 Joules. The corresponding time for the one lever swing is hence about t=0.275sec. The club head speed, at t=0.25sec, for the two lever free hinge swing is about 135 m/h.  The club head speed for t=0.275 is about 88 m/h. The free hinge hence produces a gain in clubhead speed of apox. 55%. It would have been 70% if compared at t=0.25sec.

It is therefore clear that for the same effort employed by the golfer there is a considerable gain in clubhead speed to be obtained using a free hinge, hence a flail.

The maximum speed for the flail is obtained when the two segments are in line. Moreover the inner segment then virtually comes to a stop. This indicates that it has transferred all its kinetic energy to the outer segment. This is the basic rationale behind the method - 'swinging from the inside out'.

It should be clear that the flail swing analyzed above is not quite a real golf swing since we have here taken the hinge completely free as for a real flail. However, for a human golfer there is a dead stop formed by the wrists, not allowing the outer segment  jack-knifing onto the inner segment during the downswing.