Pivot center

[Yoda]

Yoda - thank you for very much for giving me a place in your forum where I can ask probing questions, debate the validity of certain TGM concepts etc. It is very gracious of you. There is zero chance that certain others would do this, because it requires a great deal of confidence for a TGM golf instructor to allow certain TGM beliefs to be deeply explored and even challenged.

I will definitely adhere to the guideline of decorous behaviour and I would not think of insulting another forum member who has contrary opinions. I like contrary opinions because it forces me to rethink my own position, and I often change my thinking in response to insightful posts that are contrary to my own thinking.

I also will not expect you to participate in the forum and I will therefore not address my posts to you. Of course, you can post freely if you are interested and you want to selectively make a point.

My interest in participating in this forum is to learn more about TGM and about golf mechanics and biomechanics in general, and any LBG forum member should freely participate if they are interested.

Jeff,

I think your Forum will be a great success and that we will all learn a lot. I will participate when I think I can add value, but only as my time permits.

I expect the decorum to be a two-way street. Respect for opposing opinion -- however hotly debated -- will be the standard.

Regarding the clubhead kick situation. This represents my understanding at present.

Consider this composite photo.




In the final image, I have drawn a yellow line indicating where the clubshaft should be if it were ultra-rigid and incapable of flexing. I base the position of the yellow line on the direction of the central clubshaft, which has a very small amount of forward shaft lean at impact. Note that the clubhead has kicked forwards . . .

No, Jeff. The correct line is the one you drew (at my request) in your post #100. It runs from the #3 Pressure Point to the Sweetspot. Note also that the line points in the direction of the Primary Lever's fulcrum, the Left Shoulder.

The "direction of the central clubshaft" is irrelevant.

[Jeff]

Yoda - at this time point we hold contrary viewpoints. I remain open to serious, well-intentioned input from interested forum members and I hope that their input can help clarify matters. I am willing to change my viewpoint in the face of a solidly convincing argument

The problem that I have with the idea that the "sweetspot must be in line with the PP#3 point" is the "belief" that there is a causal connection between the two observed phenomenon. In a swinger, there is no thrust at PP#3. A golfer senses/monitors clubhead lag at PP#3. However, sensing clubhead lag doesn't necessarily prevent a clubhead throwaway problem where the clubhead bypasses the hands near impact, or at impact. In this situation of i) the clubhead traveling at 160mph and the ii) hands slowing down just prior to impact, I can imagine that the golfer can lose his sense of clubhead lag pressure at PP#3 whether he likes it, or not. This loss of a sense of clubhead lag pressure at PP#3 would not necessarily occur if the clubhshaft was not capable of flexing in response to the clubhead's enormous pre-impact momentum, and I could then easily imagine a straight-line relationship between the PP#3 point and the clubface's sweetspot.

Jeff.

[Mike O]

Yoda - at this time point we hold contrary viewpoints. I remain open to serious, well-intentioned input from interested forum members and I hope that their input can help clarify matters. I am willing to change my viewpoint in the face of a solidly convincing argument

The problem that I have with the idea that the "sweetspot must be in line with the PP#3 point" is the "belief" that there is a causal connection between the two observed phenomenon. In a swinger, there is no thrust at PP#3. A golfer senses/monitors clubhead lag at PP#3. However, sensing clubhead lag doesn't necessarily prevent a clubhead throwaway problem where the clubhead bypasses the hands near impact, or at impact. In this situation of i) the clubhead traveling at 160mph and the ii) hands slowing down just prior to impact, I can imagine that the golfer can lose his sense of clubhead lag pressure at PP#3 whether he likes it, or not. This loss of a sense of clubhead lag pressure at PP#3 would not necessarily occur if the clubhshaft was not capable of flexing in response to the clubhead's enormous pre-impact momentum, and I could then easily imagine a straight-line relationship between the PP#3 point and the clubface's sweetspot.

Jeff.

Jeff,
How do you think the club flexes during the golf swing? How would you differentiate between flexing and kick? If at all. How would these things change for a hitter versus a swinger? How would these things change if the plane angle was flat or upright? Look forward to your comments.

[Jeff]

Mike

Those are excellent questions. I don't know the answers.

I can understand that if a shaft flexes, that it has inherent elastic properties that will induce it to spring back to a straight line alignment. Therefore, when one sees a clubhead ahead of the hands/central clubshaft at impact - the question becomes - did that phenomenon happen because the clubhead's momentum caused the clubshaft to flex forwards or could there be a spring-back clubshaft-flex action due to the fact that the clubhead was lagging behind the clubshaft earlier in the downswing, causing the shaft to bend backwards, and now the clubshaft is simply flexing forwards in response to being previously stretched the other way (a whiplash action).

Do you have any insights to share that can differentiate between these two theoretical possibilities?

I imagine that the clubshaft should behave very differently between a hitter and a swinger. A hitter applies a push-force continuously on the clubshaft all the way through impact. I imagine that there is therefore less of a whiplash phenomenon. By contrast, a swinger induces a definitive whip lash motion, in the sense that pull-power is imparted to the clubshaft during the early-mid downswing, and no further power is imparted to the clubshaft during the near-impact phase of the downswing. At that time point, the clubshaft is moving towards impact due to the passive release of PA#2 ( due to centrifugal forces). I could imagine the clubshaft behaving very differently under those conditions.

Please share any insights you have regarding this matter.

I don't imagine that an upright versus a flat plane should have a significant effect. Do you?

Jeff.

[Mike O]

Mike

Those are excellent questions. I don't know the answers.

I can understand that if a shaft flexes, that it has inherent elastic properties that will induce it to spring back to a straight line alignment. Therefore, when one sees a clubhead ahead of the hands/central clubshaft at impact - the question becomes - did that phenomenon happen because the clubhead's momentum caused the clubshaft to flex forwards or could there be a spring-back clubshaft-flex action due to the fact that the clubhead was lagging behind the clubshaft earlier in the downswing, causing the shaft to bend backwards, and now the clubshaft is simply flexing forwards in response to being previously stretched the other way (a whiplash action).

Do you have any insights to share that can differentiate between these two theoretical possibilities?

I imagine that the clubshaft should behave very differently between a hitter and a swinger. A hitter applies a push-force continuously on the clubshaft all the way through impact. I imagine that there is therefore less of a whiplash phenomenon. By contrast, a swinger induces a definitive whip lash motion, in the sense that pull-power is imparted to the clubshaft during the early-mid downswing, and no further power is imparted to the clubshaft during the near-impact phase of the downswing. At that time point, the clubshaft is moving towards impact due to the passive release of PA#2 ( due to centrifugal forces). I could imagine the clubshaft behaving very differently under those conditions.

Please share any insights you have regarding this matter.

I don't imagine that an upright versus a flat plane should have a significant effect. Do you?

Jeff.

Do you have a photo of this long drive guy - at impact with the ball still on the face?