Lag Pressure Talk

[daniell]

If you are talking about swinging a clubhead with lighter shaft faster, I would put that increase in force into F(clubhead) instead.

Anyway, before I get myself cornered by the real experts ;-) , and after further thought, I must say I'm not too certain about F(torque), or whether an "additional force" could be there which I assumed could be caused by using different clubshaft material. I don't know how to put this, but it seems logical to me that the clubshaft material could provide some sort of spring effect at impact too. No?

cheers,

daniel

 

[daniell]

Above equation is changed to:

F (Impact) = F(clubhead) + F(clubshaft tension) + F(spring) + ?

F(clubshaft tension) : As the clubhead approached impact, the shaft bends such that on one side of the clubshaft there is tension, the other side has compression. At impact, this force is released resulting in a tension force (??).

This is still 'WIP' and may not be complete. Any other forces involved?

cheers,

daniel

EDIT: I'm not sure if this tensile force in the clubshaft is or can be released during impact. Some articles I've come across acknowledges this force in the clubshaft but at the same time states that this force is only released after the ball leaves the clubface and thus does not affect the golf ball at all.

 

[mandrin]

intuition vs science

I know it is terribly counter intuitive but indeed ball and clubhead do have a hell of a party all by themselves and the golfer is just not invited. Even Mindy Blake, a scientist golf author, who lectured in physics, did get it all wrong.

Homer Kelley also went barking up the wrong alley and like Mindy Blake passionately studied the golf swing, but only from a perspective of their own feelings, no calculations or scientific experiments.

However for those who strongly believe in ‘slow heavy hitting’ as increasing the effective mass or increasing ball departure speed will be warmly received on another TGM forum where this is still considered to be the final and objective truth.

 

[Bronco Billy]

BrocoBilly,

You really don't have to be brilliant at mechanics to work out that simple equation:

F(clubhead) = force exerted by the clubhead on the ball while travelling at a certain acceleration (F= M (effective) * acceleration);

F(torque) = additional force exerted on the ball caused by the clubshaft torque/flex (?);

F(spring) = additional force on the ball caused by the spring effect of (1) ball and (2) clubface material/design (?);

It's been almost 15 years since I studied mechanics so I may not be entirely correct although I don't think I am too far off. The three forces above should be there and can explain some of the difference in ball distance caused by using different clubshaft, balls and clubheads.

Also what is used by the industry may be simplified to a constant or coffefficient to take care of certain variable, e.g. clubshaft torque, balls and clubface material. However, in that equation I am trying to identify all the forces involved.

What I am also showing you is that the "private meeting" may not be so private after all, just in case some of the readers take that statement in the wrong context. You can include the spring effect in the "private meeting between ball and clubhead" but not the additional force caused by the clubshaft.

cheers,

daniel

EDIT: "is not" change to "may not be".

Hi There

Do You Still Believe the Golfer and the Shaft are Involved in the Private Meeting(Collision)between the ClubHead and the Ball?????? It Appears to Me the Real Experts Say NO.....

Cheers

 

[shoot54today]

I ain't a scientist, nor physicist. I just repeated what someone who researches and teaches speed in the golfswing is finding in reference to identical CHS producing varying ballspeed numbers. Don't discount that the ball is compressing and actually on the clubface for a period of time before it leaves the clubface. What if, just a what if, the CHS is 100mph at the precise moment of impact and decelerating so that the when the ball leaves the clubface it is leaving a clubface no longer at 100mph? Would the ballspeed be higher when the CHS is 100mph at impact and accelerating, so that when the ball leaves the clubface, the CHS is higher than the decelerating clubhead? Hypothetically, in example #1, when the ball actaully leaves the clubface the CHS may be 99mph and in example #2, the CHS may be 101 mph. Accelerating into impact could make a difference on ballspeed.

 

[mandrin]

I ain't a scientist, nor physicist. I just repeated what someone who researches and teaches speed in the golfswing is finding in reference to identical CHS producing varying ballspeed numbers. Don't discount that the ball is compressing and actually on the clubface for a period of time before it leaves the clubface. What if, just a what if, the CHS is 100mph at the precise moment of impact and decelerating so that the when the ball leaves the clubface it is leaving a clubface no longer at 100mph? Would the ballspeed be higher when the CHS is 100mph at impact and accelerating, so that when the ball leaves the clubface, the CHS is higher than the decelerating clubhead? Hypothetically, in example #1, when the ball actaully leaves the clubface the CHS may be 99mph and in example #2, the CHS may be 101 mph. Accelerating into impact could make a difference on ballspeed.

shoot54today,

Just think about it for a while.

The golf ball is suddenly jerked from 0 mph to 100/150 mph.

Where is that stimulus coming from? Just one possible source - clubhead.

Energy and momentum are conserved, very fundamental laws of science.

Hence if the ball gets some than it clubhead has to give it up, but sum remains equal.

Only by giving up a considerable amount of speed is the clubhead able to transfer sufficient energy/momentum and launche the ball into space such great distance.

It is simply common sense, nothing esoteric or anything sophisticated. Nothing is for free in life and so it is in science.

 

[Ringer]

shoot54today,

Just think about it for a while.

The golf ball is suddenly jerked from 0 mph to 100/150 mph.

Where is that stimulus coming from? Just one possible source - clubhead.

Energy and momentum are conserved, very fundamental laws of science.

Hence if the ball gets some than it clubhead has to give it up, but sum remains equal.

Only by giving up a considerable amount of speed is the clubhead able to transfer sufficient energy/momentum and launche the ball into space such great distance.

It is simply common sense, nothing esoteric or anything sophisticated. Nothing is for free in life and so it is in science.

Mandrin, do you think this is a closed or open system?

 

[Biffer]

I believe that there seems to be a misconception about the action of the shaft.

If you put one end of a shaft (without a clubhead on it) in a vise and pull it sideways and let go, the shaft will vibrate on it's own.

However, during a swing, with a clubhead attached, the entire shaft is moving and the weight of the clubhead is what causes the bending of the shaft.

In other words, on the downswing the shaft's flex is not moving the clubhead, but instead, the mass of the clubhead is flexing the shaft.

Two different scenarios.

 

[mandrin]

Mandrin, do you think this is a closed or open system?

Ringer,

The golf swing as such is an open system, but impact itself, for all practical purposes, a closed system.

 

[daniell]

My understanding of the force equation is now changed to:

F(Impact) = F(clubhead) + d (F(clubshaft tension) + F(spring) + ?

whether d (F(clubshaft tension) approached zero, that's another story .. ;-)

==========================

Mandarin,

If shaft bend does not have any effect on a golf swing, why can't all golfers use the stiffest flex they can get?

In reality, we know that golfers seems to be unable to launch a ball properly if the shalf is too stiff for their swing speed. Why's that? Is it simply just that a stiffer shaft is usually heavier and thus slows down one's swing?

cheers,

daniel

 

[Brian Manzella]

Important!!


1. The shaft is timing mechanism.

2. The shaft assist the golfer in creating the proper impact aligments of the clubhead and clubface for the desired shot.

That's about all folks.

Since I learn that all this "heavy hit" stuff was bad math + false feel, and I figured out what to do with the information, my teaching has improved a bunch.

Next.

 

[daniell]

Brian,

Why can't a golfer use the stiffest shaft they can get their hands on? We do know in reality that shaft flex can be too stiff for a particular swing speed, why is this so?

This is something puzzling me right now.

cheers,

daniel

 

[tongzilla]

does it make a difference that the ball gets compressed by the clubface for some time before it gains speed?

 

[shoot54today]

Below a post from Kelvin Miyuhara, a.k.a.Chainmaker, that I grabbed from the Golf Speed Forum.

"Let me throw out a theory that is very wild but I've studied this idea in tennis and it does have some validation. The theory was developed by a Chinese physicist, who insists that Newtonian physics does not adequately explain all phenomenon. Newtonian Physics is sort of limited in that the variables must be few and simplified, whereas this is not necessarily true in real life.

Case in point chains. The resistance could be calculated by knowing the variables in acceleration, velocity, wind resistance, gauges of chain moved into the air, friction from chains dragging on the ground, direction of the swing (up, down, sideways, etc.), height of person, length of limbs, etc.

There are so many variables that is become nearly impossible to calculate....or so say the physicists.

But I digress, the theory is called jumpulse and you can do a google search on it to learn more. Jumpulse refers to the sudden increase or decrease in force. I think there are people who can or who have learned to jumpulse. Tiger is one of them and Roger Federer is another one in the tennis circles. They are accelerating while the club or racquet is on the ball thereby increasing the force at impact. While probably not measurable, I'm sure they have all their force maximized at the point of contact and their body weight fully behind their shots.

Yet, ask most physicists and they'll tell you that the ball only knows the velocity of the clubhead at contact. Mass of course is the only other variable. Is this not oversimplified? What about a 6'4" golfer versus a 5'4" golfer swinging at the same speed? Also, 120 mph and accelerating at contact will definitely give you more distance than 120 mph decelerating at impact. Or maybe more correctly, it is that the guy with the least deceleration at impact is counteracting the collision of the ball better and will therefore hit the ball longer.

A speedchain is a jumpulse developer. So is an XLR8R. They teach you to suddenly increase force at the moment of impact.

Many golfers are dying out at impact. Therefore no matter what their swing speed is, they are not getting the most out of their speed.

So to me, just thinking of speed is a little oversimplified. There is an explosion you want to make as you hit the ball. Don't bother asking physicsts, they will give you the standard Newtonian answer. "

 

[daniell]

Shoot54today,

If you are implying that many physicist does not know about "Impulse" in a collision, you are wrong.

Impulse is equivalent to the change in Momentum (where momentum, p=mv). Assuming a clubhead has a velocity, V1. After coliding with the ball during an impact interval (dt), the clubhead has a reduce speed, V2. Because of the collision, there's a change in momentum of the clubhead (mV1-mV2). This change of momentum is Impulse, where

Impulse = F*dt = mV1-mV2

Do you see the force, F=ma, acting on the ball?

cheers,

daniel

Edit: yah ..yah ..yah .. minus F(friction)

 

[daniell]

If shaft bend/flex does not add any tensile force at impact, why can't a golfer use the stiffest shaft that he can find?

 

[Brian Manzella]

Cuz...cuz.

Brian,

Why can't a golfer use the stiffest shaft they can get their hands on? We do know in reality that shaft flex can be too stiff for a particular swing speed, why is this so?

1. The shaft is timing mechanism.

2. The shaft assist the golfer in creating the proper impact aligments of the clubhead and clubface for the desired shot.

 

[Biffer]

Awhile back I tried to go to a stiffer shaft (of equal weight) in my driver and the result was a loss of clubhead speed. I've tried this same experiment several times and the result was the same.

 

[mandrin]

Newtonian Physics not required – just common sense

Below a post from Kelvin Miyuhara, a.k.a.Chainmaker, that I grabbed from the Golf Speed Forum.

"Let me throw out a theory that is very wild but I've studied this idea in tennis and it does have some validation. The theory was developed by a Chinese physicist, who insists that Newtonian physics does not adequately explain all phenomenon. Newtonian Physics is sort of limited in that the variables must be few and simplified, whereas this is not necessarily true in real life.

Case in point chains. The resistance could be calculated by knowing the variables in acceleration, velocity, wind resistance, gauges of chain moved into the air, friction from chains dragging on the ground, direction of the swing (up, down, sideways, etc.), height of person, length of limbs, etc.

There are so many variables that is become nearly impossible to calculate....or so say the physicists.

But I digress, the theory is called jumpulse and you can do a google search on it to learn more. Jumpulse refers to the sudden increase or decrease in force. I think there are people who can or who have learned to jumpulse. Tiger is one of them and Roger Federer is another one in the tennis circles. They are accelerating while the club or racquet is on the ball thereby increasing the force at impact. While probably not measurable, I'm sure they have all their force maximized at the point of contact and their body weight fully behind their shots.

Yet, ask most physicists and they'll tell you that the ball only knows the velocity of the clubhead at contact. Mass of course is the only other variable. Is this not oversimplified? What about a 6'4" golfer versus a 5'4" golfer swinging at the same speed? Also, 120 mph and accelerating at contact will definitely give you more distance than 120 mph decelerating at impact. Or maybe more correctly, it is that the guy with the least deceleration at impact is counteracting the collision of the ball better and will therefore hit the ball longer.

A speedchain is a jumpulse developer. So is an XLR8R. They teach you to suddenly increase force at the moment of impact.

Many golfers are dying out at impact. Therefore no matter what their swing speed is, they are not getting the most out of their speed.

So to me, just thinking of speed is a little oversimplified. There is an explosion you want to make as you hit the ball. Don't bother asking physicsts, they will give you the standard Newtonian answer. "

shoot54today,

The force a golfer can put on the ball during impact is about 1000 times smaller than the very large inertial forces generated between ball and clubhead.

One can imagine any mystique property one likes for this puny gently little force but small is small and even a Chinese scientist can’t change that fact.

 

[Jim Kobylinski]

Awhile back I tried to go to a stiffer shaft (of equal weight) in my driver and the result was a loss of clubhead speed. I've tried this same experiment several times and the result was the same.

I went from a 60g stiff shaft to a 78g x-stiff shaft and PICKED UP swing speed.

My theory (un-proved but i have noticed it in some students and my own research) is that a lot of people's subconscious will either:

1) Slow down
2) Speed up

The golf club in order to achieve a desired result; think of it as a different form of "steering."

For instance in my case, i was playing a shaft too soft and when creating a lot of clubhead lag into impact it causing the face to hang open at impact which put an undo amount of launch angle and spin on the ball. So essentially, my "faster swings" were going SHORTER. Thus whether i knew it or not (subconscious comes into play here) i had to swing SLOWER to make the ball go FURTHER because of launch conditions.

Once i went to the heavier stiffer shaft that had the face close SOONER i was able to swing 100% and not create the launch conditions of the OLD shaft. Hence my swing speed JUMPED UP ALMOST 5MPH.

I had student who gained 4mph of swing speed with a X100 vs a S300 when comparing his 5 iron to my 5 iron.

-------------------------------------

So in your case you were having the opposite effect where the stiffer shaft caused an undesirable face angle or plane angle into the ball producing launch conditions that made the ball go SHORTER.

This is my theory and i'm sticking to it