From my perspective, the biomechanical movements of the torso/arms will be exactly the same if the clubhead has a width of 4", 8", 12" or 18" (presuming an identical club lie angle) because the essential need is to get the sole of the club parallel to the ground, and just touching the surface of the ground, at impact. In fact, if AK was swinging a dowel stick of the same length as his driver's clubshaft, but without a clubhead, his swing pattern (biomechanical movements) would likely remain the same as when he swings his regular driver. In all these cases, the hosel (and peripheral end of the dowel stick) would get to the same point at ground level. However, the distance of the hosel at its impact position from the ball-target line would depend on the width of the clubhead ( 50% of 4", 8", 12" or 18").
Regarding the COM (center-of-mass) question, it depends on the weight of the clubhead versus the clubshaft. Swinging an 18" wide clubhead may not be as easy or as fluid or as efficient or as biomechanically comfortable as swinging a 4" wide clubhead, but the clubshaft at impact must be on plane C, and a golfer must perform the standard biomechanical movements that AK performs to get it there - irrespective of the practical difficulties involved with dealing with the COM problem.
In that AK blue-lines example, one can draw a line between PP#3 and the sweetspot (which is 9" from the hosel). At impact, that sweetspot plane is much shallower than his clubshaft plane (plane C) at impact. If the club was swung post-impact onto that same sweetspot plane by the 4th parallel position, then AK would have to suddenly shallow his clubshaft plane post-impact while the clubshaft was traveling from impact to the 4th parallel (in order to rotate the clubshaft's hosel to the sweetspot plane). Can you imagine the "strange" biomechanical movements that would be necessary to achieve that goal?
From my perspective, the biomechnaical movements of the torso/arms will be exactly the same if the clubhead has a width of 4", 8", 12" or 18" (presuming an identical club lie angle) because the essential need is to get the sole of the club parallel to the ground, and just touching the surface of the ground, at impact. In fact, if AK was swinging a dowel stick of the same length as his driver's clubshaft, but without a clubhead, his swing pattern (biomechanical movements) would likely remain the same as when he swings his regular driver. In all these cases, the hosel (and peripheral end of the dowel stick) would get to the same point at ground level. However, the distance of the hosel at its impact position from the sweetspot would depend on the width of the clubhead ( 50% of 4", 8", 12" or 18").
Jeff.
Jeff,
I always associate swing plane with swing force ... centrifugal, irrespective of the shaft, which can be crooked, bent. So in my thinking, AK should align his torso/arms to the force line linking the wrist swing center - PP#2 to the sweetspot X (the COM of the club should be on this line too) - I called this the virtual club shaft. AK should prepare to swing the virtual clubshaft not the real clubshaft.
Let's do a mental experiment with my high-school physics. Suppose we have access to a swing machine with a fixed swing axis and a fixed swing plane. Let's do two experiments with your golf club with the extra long-width clubhead:
1) Put the hosel of the shaft on the fixed swing plane; and
2) Put the COM of the whole club on the fixed swing plane.
In 1) the COM of the club will try to get on plane stressing the mechanical wrist joint to the point of breaking it. Unless they allow the off-plane hinging of the clubshaft, which is to allow the clubshaft to go off plane!
In 2) the swing will work out just fine except for the usual drooping of the clubhead and the associated bending of the clubshaft.
I think that you theoretical example has no relevance to a "real" golf swing.
Remember that the sole of the clubhead must lie flat against the ground at impact - irrespective of whether the clubhead width is 4", 8", 12" or 18". That's an absolute necessity. Therefore, that absolute requirement defines the exact clubshaft angle that must exist at impact - it depends on the club's lie angle.
A golfer must achieve that "correct" clubshaft plane angle at impact. To get to that "correct" clubshaft plane at impact in a very efficient manner, one simply has to perform the same biomechanical movements that Anthony Kim performs - whether the clubhead width is 4" or 8" or 12". Of course, the stresses and efficiency associated with swinging a 12" wide clubhead is going to very different when compared to swinging a 4" wide clubhead.
I think that you theoretical example has no relevance to a "real" golf swing.
Remember that the sole of the clubhead must lie flat against the ground at impact - irrespective of whether the clubhead width is 4", 8", 12" or 18". That's an absolute necessity. Therefore, that absolute requirement defines the exact clubshaft angle that must exist at impact - it depends on the club's lie angle.
A golfer must achieve that "correct" clubshaft plane angle at impact. To get to that "correct" clubshaft plane at impact in a very efficient manner, one simply has to perform the same biomechanical movements that Anthony Kim performs - whether the clubhead width is 4" or 8" or 12". Of course, the stresses and efficiency associated with swinging a 12" wide clubhead is going to very different when compared to swinging a 4" wide clubhead.
Jeff.
Jeff,
In our mental experiments, both of them, we design the experiments to adjust the swing axis and the swing plane of the swing machine so that the sole of the clubhead to lie flat against the ground at impact!
With (1) the clubshaft in the swing plane: would be a more upright swing. (Swing axis more horizontal)
With (2) the COM of the club in the swing plane: would be a flatter swing. (Swing axis more vertical)
Both intend to start with the soled clubhead and with the soled clubhead at impact.
BTW, (2) is similar to swinging with a centered-hosel club with the clubshaft on plane.
Hybrid Mode
