Pivot center

[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?

[O.B.Left]

I think that's just the way it works . . . go check out some tennis serves . . . . it's the extension of the different levers/segments . . .

Since it impossible to thread jack this topic now:

Are all these levers here a source of power? Lets number em all in Jeffs forum. Lets start with the lower lumbar and move up to L3 (no not Lauren Conrad idiot) What about lateral moves? Is golf more rotational or lateral? Lets give the lateral move a number too. Not number 2, number tooooo. Each one with an associated pressure point. What flat wrist? Prove it dammit. "I want the truth, You cant handle the truth." "Im out of order, this whole system is out of order". "I, am not a crook"........."What we got here is a failure to communicate"........Hey can Mike O and You riff all you want in the Jeff forum? WAit DG and Jeff in a cage match on the right arm............this will be good. Pay per view maybe. Ultimate TGM.

Just when I was starting to understand TGM! "Looks like I picked a bad day to give up chewing gum".

[Jeff]

Mike - I don't have an image with the ball on the clubface. I only have the still photos from GD magazine. I really need a slow-mo swing video of his swing (captured at >500 frames/second) to be able to get a capture image of the ball on the clubface. Why is it important?

By the way, I looked up the topic of "flexible shafts" in Jorgensen's book "The Physics of Golf". He is very vague in his calculations and he claims that shaft flexibility can increase clubhead speed by 3%. He does not discuss whether any increased forward shaft flex at impact is solely due to the whiplash phenomenon of shaft flex or whether is it due to the "effective mass of the clubhead" at impact.

I am going to PM nmgolfer, who is a forum member, and ask him whether he can shed any light on this issue.

Whether the forward shaft flex at impact is due to shaft flexing (whiplash effect) or due to the clubhead's large momentum (due to its >160mpmh speed) at impact, it seems to be an incontestable fact that the peripheral end of the clubshaft is flexing forward. What is interesting to me, is that the clubhead/clubface is not-in-line with the V-groove of the hands. Normally, when analysing swing videos of professional golfers using my V1 Home software program, one doesn't see the clubhead ahead of the hands at any time point during the downswing, and I don't think that the forward shaft flex is intentional. If Jamie was intentionally flipping his hands at impact to get the clubface to go upwards into the teed ball, then the V-groove of the hands should be in-line with the sweetspot of the clubface.

Jeff.

[Bigwill]

Is there a chance that the clubshaft bending that far forward is a optical illusion caused by the shutter speed of the camera or something? I ask because I've seen some high-speed camera slow-mo of Sadlowski's swing, and the shaft dosen't kick anywhere near where that picture has it. I know it flexes during the swing, but not that much, does it??


BTW, Jeff, here's some slow mo of Jamie, at about the 30 second mark.

[bond007]

Is there a chance that the clubshaft bending that far forward is a optical illusion caused by the shutter speed of the camera or something? I ask because I've seen some high-speed camera slow-mo of Sadlowski's swing, and the shaft dosen't kick anywhere near where that picture has it. I know it flexes during the swing, but not that much, does it??


BTW, Jeff, here's some slow mo of Jamie, at about the 30 second mark.

I caught this slo-mo shot at the 36sec. interval (right at impact) and the shaft is pretty much in line with the left arm.
I have seen some ultra slo-mo shots that show some really distorted shaft positions throughout the swing on some players that don't come close to this young man's speed. Don't believe you would see this kind of distortion on shorter shafts. The longer driver shafts, even though they are tipped very firm, have what I believe to be a recoil effect immediatley after impact.

[Augusta Golf]

Well said but I'm still putting you on my list! No not that list- this list I went to look at Jeff's swinging video but got sidetracked with Sasha is a goddess.

Mike, you apparently are not taking the red pill along with the blue pill as we agreed per your outpatient diagnosis.

[Yoda]

I have seen some ultra slo-mo shots that show some really distorted shaft positions throughout the swing on some players that don't come close to this young man's speed.

Homer said that the degree of clubshaft distortion didn't matter.

"The clubshaft can look like a snake," said he, "but the sweetspot is still trying to get in line with the #3 pressure point."

[Jeff]

Bigwill/Bond007

I agree that one cannot trust what one sees when looking at capture images of swing videos - especially when the frame rate is only 30 frames/second. I have seen swing videos where the clubshaft was bent 90 degrees. The reason is due to the fact that the camcorder is operating at 30 frames/second and it has multiple moving images occurring within that single frame time period (1/30th second) and the camcorder simply recreates a composite image according to the camera manufacturer's algorithm. Even the Bizhub Swingvision camera, which operates at 500 frames/second, may result in distortion when dealing with fast club speeds.

Here are capture images from that slow-mo section of the Sadlowksi swing video.



I put in image 1 for fun - to show his amazing clubhead lag.

Images 2-5 show the clubshaft movement through the impact zone. There was no frame that captured the clubshaft at impact.

Note how blurred the clubshaft images are - I cannot trust their accuracy even though this is a slow-mo swing video.

However, there is an interesting point. Look at the clubface sweetspot in relationship to the hand angle. I can believe that one can draw a straight line between the sweetspot and PP#3 and I can believe that the sweetspot is trying to get inline with PP#3. However, that GD photo of Jamie post-impact didn't look right to me - the hand angle didn't look right relative to the sweetspot. I still think that the sweetspot should have been where I drew the yellow line. I don't think that we can resolve this issue because even the GD photos, which were presumably taken with camera that has a very high shutter speed, may be distorting reality.

Jeff.

[O.B.Left]

Jeff

Know what you mean, interesting note and with many implications. Horse racing for instance.

But the GD photos are super sharp and one normally tends to go with that for accuracy no? Could the video blur be hiding a bend? it doesnt appear so but.. Why would the film show a sharp in focus bend instead of just a blur?

O.B.

[Jeff]

The video blur could be hiding a "true" bend.

It shows a sharp focused clubshaft because the camcorder's inbuilt algorithm instructs the camera to produce a composite photo that is compositionally coherent when faced with multiple blurred moving images. It chooses one-of-many clubshaft images that occur within the time space of one frame as being a representative clubshaft image.

I think that one can trust the accuracy of the Tiger Woods Nike Commercial swing video because the frame rate was 4,000 frames/second. Interestingly, there is no clubshaft bend post-impact in that video.

I don't know if the GD photo series was made with a still digital camera, which can have a fast shutter speed of 1/8,000th second and where each image is a single frame captured at 1/8000th second. If the images were captured with a still camera operating at >1/8,000th second, then they should be accurate.

Jeff.