The XYZ axes, and what contributes the most to clubhead speed (now w/p5 VIDEO)

[Brian Manzella]

Can you clarify this statement

"In Alex's opinion, fast closure rates contribute greatly to rotation on the y-axis (see picture below) which ENSO-pro shows to contribute about 80% of the overall club head speed (the largest contributor)."

Looking at the picture of Bubba Watson, if you look at the first driver position (just past delivery) to the impact position, are you saying the faster you close this distance the faster the clubhead speed is (which seems relatively obvious) OR are you taking about the rotation of the face(the basis of lots of discussion the past week) from the positions shown contributing 80%?

ALPHA (roation about the Y axis) is exactly what I showed in the picture below (and in the thread starter)...

All Alex Dee is saying (and no peanut gallery, I didn't get it wrong) was that GAMMA (z axis, roc) contributes greatly to ALPHA-Y velocity.

Not sure...but I thought Alex was saying a high ROC (contributing nothing net to the clubhead speed by itself) DOES allow for a high y axis movement rate (and that being about 80% of clubhead speed).

That's it.

How on earth could beta or gamma have any significant effect on clubhead speed? Alpha IS clubhead speed!

Baloney!

Beta alone has to be around 15%.

Don't these 2 sentences contradict each other? If fast closure rates contribute to y-axis rotation which is the largest contributor to clubhead speed, then I don't see how the first sentence still holds.

That said, I think Wulsy is right...

No, he isn't.

How can beta not have an effect on clubhead speed? The force across the shaft out of the hand plane would make the clubhead fly to the ball.

No kidding....

Either way - I still can't see how those 2 sentences in the thread starter can co-exist peacefully.

I can....and after I go through all the trouble of spelling it out....what do I get?

I agree with Birly. More detail is needed to flesh out the apparent contradiction. I suspect the devil is in the definitions.

If you spend any more time locked in that closet, you will go completely blind.

Maybe I am a little lost on the letter designations but its my contention you want less "Z" rotation near impact.....is that a crazy statement or just more of my misunderstanding the pictures?

It's just more of your misunderstanding.

There's a lot of that going around.

a. Clubface on a table top, clubface vertical to the table at "address," body straight up and down, normal stading attitude.. 20 inch scrape backswing, 40 inch forward swing. Score lines of the FACE stay 90 degrees to the table. ZERO z axis/GAMMA rotation.

b. Clubface on a table top, clubface vertical to the table at "address," body straight up and down, normal standing attitude. On the 20 inch scrape backswing face opens 30 degrees. On the 40 inch forward swing the face closes 60 degrees and finishes 30 degrees closed to the table. There is OBVIOUS z axis/GAMMA rotation. We will call the amount (which is dependent on the speed) XXX amount.

c. Clubface on a table top, clubface vertical to the table at "address," body straight up and down, normal standing attitude. On the 20 inch scrape backswing face opens 30 degrees. On the 40 inch forward swing the face rotates the EXACT same amount that caused the face to rotate 60 degrees to the table and finished 30 degrees closed to the table. THE SAME EXACT XXX z axis/GAMMA rotation. But....the golfer slides the tailbone a hair forward, open the hips a bunch, the shoulders a decent amount, adds right side bend, moves toward back extention......The face does not rotate as much to the table.

Got it?



Somebody needs to vet RH's hair.

 

[puttmaster]

c. Clubface on a table top, clubface vertical to the table at "address," body straight up and down, normal standing attitude. On the 20 inch scrape backswing face opens 30 degrees. On the 40 inch forward swing the face rotates the EXACT same amount that caused the face to rotate 60 degrees to the table and finished 30 degrees closed to the table. THE SAME EXACT XXX z axis/GAMMA rotation. But....the golfer slides the tailbone a hair forward, open the hips a bunch, the shoulders a decent amount, adds right side bend, moves toward back extention......The face does not rotate as much to the table.

Got it?

Yep -- even I understand that explanation!

 

[James Marshall (Hogan1953)]

Where does all this leave the pivot's contribution to the speed of the clubhead at impact? We know through Steven Nesbit's work and Brian's help that 75% of the work of the pivot goes into simply moving the body, where does that leave the other 25%? What contribution is it making to the speed of the clubhead?

The pivot's role seems to be relegated more to one of an initiator in the transition, an alignment tool and a carrier of the arms/hands and club to the ball so that the speed generated by the three torques doesn't get wasted by hitting the ground behind the ball.

 

[cwdlaw223]

"Not sure...but I thought Alex was saying a high ROC (contributing nothing net to the clubhead speed by itself) DOES allow for a high y axis movement rate (and that being about 80% of clubhead speed)."

The problem for the reader in the statement above is in the transitive property being stated as follows: (a) RoC contributes greatly to high y axis movement rate, (b) high y axis movement rate increases clubhead speed, and therefore (c) RoC contributes to clubhead speed by influencining the y axis which is 80% of the clubhead speed.

The post says that RoC does NOT contribute to clubhead speed by itself but then it "greatly" increases the y axis movement rate and y axis movement rate accounts for 80% of clubhead speed. If something A is "greatly influencing" another something B that accounts for 80% of clubhead speed then someting A increases clubehad speed.

The adjective "greatly" is what is throwing me off because if y axis is greatly affected by Roc and y axis accounts for 80% of clubehead speed, one would presume that RoC plays a role in clubehad speed.

 

[gmbtempe]

"Not sure...but I thought Alex was saying a high ROC (contributing nothing net to the clubhead speed by itself) DOES allow for a high y axis movement rate (and that being about 80% of clubhead speed)."

The problem for the reader in the statement above is in the transitive property being stated as follows: (a) RoC contributes greatly to high y axis movement rate, (b) high y axis movement rate increases clubhead speed, and therefore (c) RoC contributes to clubhead speed by influencining the y axis which is 80% of the clubhead speed.

The post says that RoC does NOT contribute to clubhead speed by itself but then it "greatly" increases the y axis movement rate and y axis movement rate accounts for 80% of clubhead speed. If something A is "greatly influencing" another something B that accounts for 80% of clubhead speed then someting A increases clubehad speed.

The adjective "greatly" is what is throwing me off because if y axis is greatly affected by Roc and y axis accounts for 80% of clubehead speed, one would presume that RoC plays a role in clubehad speed.

head spinning...................heading to the range to trying and get the club face onto the back of the ball

 

[birly-shirly]

OK. I'm not too proud to admit it.

I'm still confused.

Am I supposed to read some fundamental distinction into the meanings of "allow for" and "contributes"?

The Dee direct quote in the starter explains why increased ROC doesn't significantly increase CH speed. Maybe it would help to give Dee's explanation of how GAMMA/ROC contributes greatly to ALPHA-Y velocity.

 

[Brian Manzella]

I said in my previous post, I know how all by myself, and I ain't giving it away.

 

[drewyallop]

Where does all this leave the pivot's contribution to the speed of the clubhead at impact? We know through Steven Nesbit's work and Brian's help that 75% of the work of the pivot goes into simply moving the body, where does that leave the other 25%? What contribution is it making to the speed of the clubhead?

The pivot's role seems to be relegated more to one of an initiator in the transition, an alignment tool and a carrier of the arms/hands and club to the ball so that the speed generated by the three torques doesn't get wasted by hitting the ground behind the ball.

I suggest a close reading of Nesbit's paper again. Nesbit's model, among other things, measured how much work was being done by each body segment in the downswing. For example the model shows that the hips, thoracic spine and lumbar spine segments of a scratch golfer do 72% of the work in the downswing and the shoulders and arms do most of the rest. Full results are here http://www.jsportscimed.org/vol4/n4/18/v4n4-18pdf.pdf
http://www.jsportscimed.org/vol4/n4/18/v4n4-18pdf.pdf
Since work is the transfer of energy into the club it follows that the pivot of hips and spine as described in the paper is of highest importance. Note that this is true even if only 20% of the body work gets to the club.

 

[Brian Manzella]

Only 25% efficient....


But on a separate note, you can swing your arms with NO PIVOT way faster than you think.


...not giving up the goods until some folks at least take some good guesses....

 

[Virtuoso]

Only 25% efficient....


But on a separate note, you can swing your arms with NO PIVOT way faster than you think.


...not giving up the goods until some folks at least take some good guesses....

2 things that I have observed from personal experience that people absolutely don't want to accept:

1. You can have a high closure rate, as measured, and still "look" like Ben Hogan or Nick Price through impact.

2. If you try to manually reduce your rate of closure, as measured, to an extreme extent, you will almost break your wrists, you will only drop the actual number by about 400 deg/sec (unless you just chip it 120 yds with your 6 iron), and you will be OB right on every hole in your next round unless you get the clubface ridiculously closed at transition.

 

[Brian Manzella]

2 things that I have observed from personal experience that people absolutely don't want to accept:

1. You can have a high closure rate, as measured, and still "look" like Ben Hogan or Nick Price through impact.

2. If you try to manually reduce your rate of closure to an extreme extent, you will almost break your wrists, you will only drop the actual number by about 400 deg/sec (unless you just chip it 120 yds with your 6 iron), and you will be OB right on every hole in your next round unless you get the clubface ridiculously closed at transition.

So brilliant...

Sounds like you tested a few times on something....

 

[Kevin Shields]

2 things that I have observed from personal experience that people absolutely don't want to accept:

1. You can have a high closure rate, as measured, and still "look" like Ben Hogan or Nick Price through impact.

2. If you try to manually reduce your rate of closure to an extreme extent, you will almost break your wrists, you will only drop the actual number by about 400 deg/sec (unless you just chip it 120 yds with your 6 iron), and you will be OB right on every hole in your next round unless you get the clubface ridiculously closed at transition.

Your the man

 

[Virtuoso]

So brilliant...

Sounds like you tested a few times on something....

...yes, I have access to some toys. I can't say a whole lot except that, imo, you guys are on the right track--the measurements are good and the swing stuff is ground breaking.

 

[mandrin]

Birly,

I think that "fast closure rates contribute to y-axis rotation" is equivalent to saying that "fast closure rates" i.e. greater twisting of the grip along the axis of the shaft (gamma) accelerates the rotation about the coupling point, i.e. bottom of grip passing top grip or, in Enso speak, y-axis acceleration. To me it is intuitive that twisting the grip on the way down will accelerate the y-axis velocity. So let's grab a club. Let the arms drop from the top with no twisting. Now let the arms drop with twisting. Feel acceleration?

It would be good if a proof from Newtonian dynamics could be provided for this. Mandrin?

Drew

Drew,

One has to be careful going too much in detail when basing oneself on math models. The math model might assume two slender rigid bodies for arms and club, connected via a revolute joint or perhaps via a spherical joint.

However a real golfer is way more complicated. He has two hands on the handle and the wrist joints have an offset relative to the club shaft. Therefore strictly speaking we have a short additional segment between each arm and the shaft.

Whereas in a math model the rotation of the shaft around its longitudinal axis has no bearing on any other possible movement of the shaft this can't be readily reproduced by a real golfer without introducing additional torques.

There are several actions which can be performed by the hands/ wrists either individually or in combination and to model accurately mathematically the actions of the hands/wrists is not an easy task.

 

[bluebird]

I'll take a shot, even though i see the heavyweights have arrived. If the handpath is on the same plane as the clubhead, then adding Gamma would do very little to increase club speed. But the more the hand path is offset from the plane of the head, then there is considerably more travel of the clubhead for each degree of Gamma rotation. If this increase can be used by cancelling out the timing aspects, by the pivot / hip and shoulder opening, then we have a controllable improvement. So this will only work with low hands. So even though the hands have added Gamma the clubhead velocity increase is in the Alpha.

 

[drewyallop]

I'll take a shot, even though i see the heavyweights have arrived. If the handpath is on the same plane as the clubhead, then adding Gamma would do very little to increase club speed. But the more the hand path is offset from the plane of the head, then there is considerably more travel of the clubhead for each degree of Gamma rotation. If this increase can be used by cancelling out the timing aspects, by the pivot / hip and shoulder opening, then we have a controllable improvement. So this will only work with low hands. So even though the hands have added Gamma the clubhead velocity increase is in the Alpha.

Bluebird and Mandrin,

This is a fascinating thread. The low hands thought seems intuitively right and the scientists agreed at ASII that "keeping the hands "under the table" was essential. For some reason I keep thinking about MacKenzie's paper on the clubface automatically squaring when the clubhead plane is below the plane traced out by the left wrist bone at the start of the downswing. Could the mechanics of this be somehow analagous to what is happening when gamma is applied later in the downswing (see the illustration of the lever arm in MacKenzie's paper)?

As for those still confused, forget about the science and just apply a twistaway as described in NSA2 during the downswing. I will be surprised if you do not experience increased acceleration of the clubhead.

Drew

 

[drewyallop]

Only 25% efficient....


But on a separate note, you can swing your arms with NO PIVOT way faster than you think.


...not giving up the goods until some folks at least take some good guesses....

Course you can. I do it all the time (joke).

Seriously, I have been in the bush many times with virtually no room to backswing. Just lift the club up, apply right shoulder/arm/hand force and gamma the living crap out of it. Clubhead speed, impact and distance makes you wonder why you just don't do it on all swings. BTW torso does eventually turn but it is supporting only, not driving.

 

[Brian Manzella]

Thanks to all for your responses.

But basically, Mandrin gave everyone the answer.

YOU WILL MOVE ALL SORTS OF THINGS WHILE YOU ARE ROTATING THE CLUBHEAD ABOUT THE Z AXIS.

 

[Brian Manzella]

The only people who don't get it now are looney.

 

[bendet3]

As for those still confused, forget about the science and just apply a twistaway as described in NSA2 during the downswing. I will be surprised if you do not experience increased acceleration of the clubhead.

Drew

THANK YOU!