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

[Brian Manzella]

According to Alex Dee of Fujikura, ENSO-pro measurements are showing that closure rate is NOT adding significantly to clubhead speed.

"You have to keep in mind that the shaft is deformed at impact and not a straight shaft. Most people think that when they rotate the (grip end of the club), the head will rotate about the hosel. Not true. Because the shaft is drooping toe down at impact, it behaves like a center shafted putter. Imagine a center shafted putter and what happens when you rotate the handle: the portion of the face that is from the heel to the shaft is actually rotating away from target and taking away head velocity (due to the [grip] rotation). We see closure rates maybe adding about 2mph for near center impacts. However, since turning the handle on a deformed club makes the hosel move backwards about 2mph, the velocities basically cancel out."

​

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).

Thanks so much to Alex for all his help, and to Mike Finney for his many communications with Alex, and to Dr. Steven Nesbit for all his help the last couple of years.

POPSE (Project 1.68)...the best information on how the golf swing really works, and what to do with the information.

 

[hp12c]

Im not a very smart man and for me to try and contribute to this thread will be a "no bueno", I will just read and glean as much as I can.

 

[gmbtempe]

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%?

 

[dbl]

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).

 

[wulsy]

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

 

[birly-shirly]

According to Alex Dee of Fujikura, ENSO-pro measurements are showing that closure rate is NOT adding significantly to clubhead speed.

[...]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).[...]

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...

 

[Kevin Shields]

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

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.

 

[coach]

Just to toss this out there
How does the torsional (rotational) and the longitudinal (bending) -stiffness effect the impact condition ?
The alignment the clubface assumes at impact is significantly influenced by both the material properties and geometry of the shaft, so I would think that the XYZ could be greatly effected by shafts... probably why getting fitted properly using trackman or other top devices could make big difference in impact condition

 

[drewyallop]

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...

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

 

[birly-shirly]

Drew - I see what you're saying, but the twist is defined as a twist about the longitudinal axis of the shaft. There's no reason why your intuitive physical movement aimed at a twist will actually precisely coincide with the shaft as axis - so it would be difficult in your experiment to separate out whether the felt acceleration is due to the twist, or just unintentional y-axis torque.

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

 

[drewyallop]

Drew - I see what you're saying, but the twist is defined as a twist about the longitudinal axis of the shaft. There's no reason why your intuitive physical movement aimed at a twist will actually precisely coincide with the shaft as axis - so it would be difficult in your experiment to separate out whether the felt acceleration is due to the twist, or just unintentional y-axis torque.

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

I modified it a bit Birly. Make any sense?

 

[birly-shirly]

Drew - yes, makes sense.

I don't know whether you're right or not - BUT IF YOU ARE - then surely your twist DOES add to clubhead speed and therefore contradicts the first sentence of the thread starter.

But something strange has happened. That first sentence is now a double negative - "NOT NOT adding"? Did anyone really say that? I don't think I subconsciously edited the quote to a single negative when I first posted, quoting the thread starter.

 

[drewyallop]

Just to toss this out there
How does the torsional (rotational) and the longitudinal (bending) -stiffness effect the impact condition ?
The alignment the clubface assumes at impact is significantly influenced by both the material properties and geometry of the shaft, so I would think that the XYZ could be greatly effected by shafts... probably why getting fitted properly using trackman or other top devices could make big difference in impact condition

Good point coach. I think Michaels Jacobs and Sasho MacKenzie talk about this in their reports of clubhead lead and droop deflection at impact. Both deflections are significant; droop, for example, can result in up to 5 degrees of face closure. Importantly, the magnitudes of both deflections vary with shaft stiffness (and I assume other shaft properties) and swing speed. From this it would seem that getting the right shaft is important for controlling impact conditions, especially for people that can swing fast. But note that all else being equal shaft stiffness does not increase clubhead speed.

I think Paul Woods at ASII said the best way to find the right shaft is to experiment and chose the one that allows you to time the release for best impact. I think this is equivalent to saying "pick the one that makes the ball go farther".


Drew

p.s. If true then much of the "science" around shaft fitting systems is just marketing voodoo.

 

[66er]

Ok I nearly got the apha and gamma down, but when I tumble I shut down the clubface big time, doing it wrong?

 

[coach]

"pick the one that makes the ball go farther".
.

Simple rule to live by.....

 

[cwdlaw223]

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

 

[gmbtempe]

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?

 

[dbl]

Just a amateur golfer here, but the faster ROC (z, gamma) I try for, the faster the y (alpha) I get (or maybe need). For someone who like me has dialed things down a bit for "control" going at things harder is better.

 

[watson08]

"According to Alex Dee of Fujikura, ENSO-pro measurements are showing that closure rate is NOT adding significantly to clubhead speed.


"You have to keep in mind that the shaft is deformed at impact and not a straight shaft. Most people think that when they rotate the (grip end of the club), the head will rotate about the hosel. Not true. Because the shaft is drooping toe down at impact, it behaves like a center shafted putter. Imagine a center shafted putter and what happens when you rotate the handle: the portion of the face that is from the heel to the shaft is actually rotating away from target and taking away head velocity (due to the [grip] rotation). We see closure rates maybe adding about 2mph for near center impacts. However, since turning the handle on a deformed club makes the hosel move backwards about 2mph, the velocities basically cancel out." "

Alex seems to be discussing gamma & not alpha in the paragraph above. He is saying that gamma by itself is essentially a wash for producing club head speed. Alpha rules club head speed. But, Brian's statement seems to infer that gamma contributes to alpha greatly, i.e., they are not independent. Correct?

 

[cwdlaw223]

Stiffer shaft = less toe drop/droop = less face closure

That's might be why I hit the ball more accurately with X flex shafts. (Played like crap today however).