Lag Pressure Talk

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If you were to swing a golf shaft by itself, no clubhead attached, the bend/flex would be pretty near zero. So, it's mainly the weight of the clubhead that is causing the shaft to bend. Question is, what is the name of the force that makes the clubhead bend the shaft? :confused:
 
If you were to swing a golf shaft by itself, no clubhead attached, the bend/flex would be pretty near zero. So, it's mainly the weight of the clubhead that is causing the shaft to bend. Question is, what is the name of the force that makes the clubhead bend the shaft? :confused:
Biffer,

Weight of the clubhead invokes gravity so let’s use mass instead.

The bending is seemingly caused by that funny elusive non-existing centrifugal force. :D It operates through the cog offset of the clubhead, creating a fairly large torque.

I find it amusing that so many deny, sometimes even with a religious fanatism, its existence, yet they and everyone else refer to it as if it really existed. Just think of the many engineering applications/apparatus using ‘centrifugal’ as qualifier. ;)
 

Jim Kobylinski

Super Moderator
Re-read what Jim wrote in his post. He swung harder with the stiffer shaft because he didn't have to time the kick of the whippier shaft--this made him subconsciously swing slower. You've confused cause and effect.

This is exactly what i meant, i had to swing slower (whether it was consciously or not) so that the face wouldn't hang open during the impact interval causing extra loft/launch/spin. Essentially, as brian has mentioned, the shaft wasn't "timed" right for my speed. So i had to slow the speed to time the shaft.

Once i got the stiffer shaft i was able to swing at a faster speed because the shaft was timed correctly.
 
Quote from Mandrin .. "Nesbit/Serrano mention the clubhead to return to its undeflected position near impact. Golf club experts/photographic evidence however will show that the shaft bends forward at impact. Not due to a forward kicking of the shaft but due to an inertial torque caused by the centrifugal force acting through the offset center of mass of the clubhead.

Mandrin,

Shouldn't it be both Centrifugal Force and Shaft Kick? After all, as the shaft bends there is stored energy and as the shaft bends forward at impact, this stored energy must have been released somehow..

cheers,

daniel
 
Mandrin, lets see if I have this right. The strained club unbends at some point during the downswing and very soon after, the increasing CF creates the forward bend prior to impact?

Could a golfer resonably expect to time these events to happen concurrently (or close to it) or is this what proper clubfitting accomplishes?

Is this how a snap release generates the clubhead speed?
 
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Quote from Mandrin .. "Nesbit/Serrano mention the clubhead to return to its undeflected position near impact. Golf club experts/photographic evidence however will show that the shaft bends forward at impact. Not due to a forward kicking of the shaft but due to an inertial torque caused by the centrifugal force acting through the offset center of mass of the clubhead.

Mandrin,

Shouldn't it be both Centrifugal Force and Shaft Kick? After all, as the shaft bends there is stored energy and as the shaft bends forward at impact, this stored energy must have been released somehow..

cheers,

daniel
daniel

A spring is a spring only if it is allowed to act as a spring.

Keep a grip firmly in both hands and ask someone to deflect the clubhead.

Put the club in a vise and do the same.

Notice any difference? :p
 
Mandrin, lets see if I have this right. The strained club unbends at some point during the downswing and very soon after, the increasing CF creates the forward bend prior to impact?

Could a golfer resonably expect to time these events to happen concurrently (or close to it) or is this what proper clubfitting accomplishes?

Is this how a snap release generates the clubhead speed?
Vicious Circle ,

Concurrently - existing or happening at the same time.

Bending and unbending really can’t occur at the same time. :D
 
Biffer,

Weight of the clubhead invokes gravity so let’s use mass instead.

The bending is seemingly caused by that funny elusive non-existing centrifugal force. :D It operates through the cog offset of the clubhead, creating a fairly large torque.

I find it amusing that so many deny, sometimes even with a religious fanatism, its existence, yet they and everyone else refer to it as if it really existed. Just think of the many engineering applications/apparatus using ‘centrifugal’ as qualifier. ;)

Ok, thanks, mandrin. :)
 
daniel

A spring is a spring only if it is allowed to act as a spring.

Keep a grip firmly in both hands and ask someone to deflect the clubhead.

Put the club in a vise and do the same.

Notice any difference? :p

Mandrin,

I have come to the conclusion that the change in shaft bend at impact does not have any influence on the force delivered to the ball at impact. To be more exact, it may be so small that it can be assumed to be zero. Thus the examples above does not apply. :)

However, I'm not so certain about the stored tensile energy/force (pardon me if I don't use the exact terms as it's a long time since I studied mechanics) in the clubshaft. I understand that slow motion cameras shows the clubshaft bending away from the target early in the downswing and it bends towards the target at impact. If this is correct, then the bend in the clubshaft must have some stored tensile force early in the downswing which releases and then goes negative. Depending on impact conditions, it can help or act against CF.

Why is this force ignored? In your modelling, there is zero shaftbend and thus zero tensile force which in essence is a super stiff shaft. But in reality, the clubshaft is not so stiff. It does bend, doesn't it?

cheers,

daniel
 
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daniel

A spring is a spring only if it is allowed to act as a spring.

Keep a grip firmly in both hands and ask someone to deflect the clubhead.

Put the club in a vise and do the same.

Notice any difference? :p

Mandrin,

I have come to the conclusion that the change in shaft bend at impact (due to clubhead impacting the ball) does not have any influence on the force delivered to the ball at impact. To be more exact, it may be so small that it can be assumed to be zero. Thus the examples above does not apply. :)

However, I'm not so certain about the stored tensile energy/force (pardon me if I don't use the exact terms as it's a long time since I studied mechanics) in the clubshaft. I understand that slow motion cameras shows the clubshaft bending away from the target early in the downswing and it bends towards the target at impact. If this is correct, then the bend in the clubshaft must have some stored tensile force early in the downswing which releases and then goes negative.

Why is this force ignored? In your modelling, there is zero shaftbend and thus zero tensile which in essence is a super stiff shaft. But in reality, the clubshaft is not so stiff. It does bend, doesn't it?

cheers,

daniel
 
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Vicious Circle ,

Concurrently - existing or happening at the same time.

Bending and unbending really can’t occur at the same time. :D

Another try.

Shaft goes from ) to | to ( ,,, with the | shaft condition travelling some distance. Can this distance travelled be reduced to a golfers advantage?
 
shaft flex?

Another try.

Shaft goes from ) to | to ( ,,, with the | shaft condition travelling some distance. Can this distance travelled be reduced to a golfers advantage?

Wouldn't this be achieved simply through a stiffer shaft? :confused:

I think whether or not it is to the golfer's advantage or not would depend on the golfer. If a shaft was already too stiff, the feel (or "timing mechanism") will be thrown off even more, and definitely would not benefit the golfer.
 
Wouldn't this be achieved simply through a stiffer shaft? :confused:

I think whether or not it is to the golfer's advantage or not would depend on the golfer. If a shaft was already too stiff, the feel (or "timing mechanism") will be thrown off even more, and definitely would not benefit the golfer.

Confused also. Agreed that it depends on the golfer. I would think that the shorter the duration of the | phase, the higher (slightly) the clubhead speed would be. Is this the objective when fitting shafts?
 
two different things...

Confused also. Agreed that it depends on the golfer. I would think that the shorter the duration of the | phase, the higher (slightly) the clubhead speed would be. Is this the objective when fitting shafts?

Ahh, there is a difference between the duration of the | phase, and how far the shaft travels in this phase. For example, if a shaft tip moved 3 inches in one second, it would be moving a lot faster than a shaft that moved 1 inch in half a second. It would seem to me that the first instance is a softer shaft, while the second is a stiffer one. In your above post, you talked about reducing the distance, but it would be reducing the interval that would add clubhead speed.

My physics knowledge is only high-school based, so please correct me if I'm wrong here.
 
Mandrin, You da man (and puttmad too), as confirmed by BM reply too.
Your dedication is second to none in this forum, you are the most valuable poster here, some poster sometimes holding your back, pls keep your head up. I teach my son in my retirement year, and willing to search for the truth in golf swing, as you know in reality that golf swing is not as simple as ping man or catapult with a fixed post (left shoulder in human), it has multiple posts, these post is in dynamic movement follow shoulders swing patern, weight shift and spine angle movement. With that said, would you please put these parameters to your equations (at least 2 posts), with some rusty engineering background I couldn't do it, please simplify the engineering terms and if that were necessary please give us some links so we can learn.
 
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