Heavy hit

[drewitgolf]

Is that possible? Is it possible to ensure that the clubhead does not decelerate during impact by maintaining a lot of clubhead lag pressure (presumably by increasing right triceps muscle push-tone force during impact)?

Not possible. It is all about resisting the inevitable.

[Mike O]

Golfbulldog - you are correctly identifying my question.

You wrote-: "the idea that if you can minimise the deceleration of the clubhead during impact "zero deceleration is what would give maximum ball speed...".

Is that possible? Is it possible to ensure that the clubhead does not decelerate during impact by maintaining a lot of clubhead lag pressure (presumably by increasing right triceps muscle push-tone force during impact)? When PA#2 releases, there is presumably a sense of decreased lag pressure at PP#3. I presume that a good golfer instinctively increases right triceps isometric muscle tone to prevent any decrease in the "feel" of lag pressure at PP#3 (during the PA#2 release process) from happening. Is that true considering how fast PA#2 releases? Is that controllable/trainable?

Jeff.

Jeff, To keep it simple - As you are referring to right triceps muscle push- you'd be limiting your discussion to hitting.

If you lose lag pressure when you release an accumulator- you've got problems!

[Jeff]

DIG

I didn't think that it is possible. I was wondering whether people were postulating varying amounts of right arm thrust power for a given amount of right wrist bend at impact (= given amount of forward shaft lean = given amount of clubhead lag) even though swingers do not actively hit.

Jeff.

[coolstv88]

Jeff, To keep it simple - As you are referring to right triceps muscle push- you'd be limiting your discussion to hitting.

If you lose lag pressure when you release an accumulator- you've got problems!

Couldn't this slight increase in right tricept muscle force also be atributed to extensor action, it is impossible for the right tricept to ever be completly inert as some force must be exterted to creast extensor action to take the slack out of the assembly.

[12 piece bucket]

DIG

I didn't think that it is possible. I was wondering whether people were postulating varying amounts of right arm thrust power for a given amount of right wrist bend at impact (= given amount of forward shaft lean = given amount of clubhead lag) even though swingers do not actively hit.

Jeff.

Jeff . . . Homer said that he felt lag pressure so strong that he felt like he could lift himself off the ground . . . BUT he also said that lag pressure is measured out in ounces not pounds. That a pound of lag pressure would be too much to sustain . . . hmmmmmmm . . . . not really sure how to reconcile that.

I'm not sure that in your above post you actually are equating lag pressure with shaft lean . . . . there is a connection there . . . however . . . . . . . . . shaft lean must also be metered out in appropriate amounts for the shot at hand and the club in hand . . . . . nicking the loft with shaft lean on the short irons works . . . . but maybe not such a good concept with the longer less lofted irons . . . see Lee Trevino . . . .

This is one of the reasons you want to be sure that you take your grip at fix . . . . a "leany" fix maybe really good with the short irons . . . but you may need the loft with the longer clubs so back of the lean and swing appropriately.

There is "accumulator lag", "lagging components", a "lagging clubhead" and LAG PRESSURE. You don't have to have ooodles of the first 3 to have the last one. Pressure is . . . well pressure. Swingers generally will feel less pressure generally due to the loading and the pressure point loading on the knuckle and moving back to the fleshy pad (or not moving).

[okie]

12P,

Do you think this is where the club manufacturers have done a number on us? I feel as my mechanics get better my ball flight becomes lower. I know how to fix this...at...fix, but I love the crunch that a "leany" shaft provides. Is that why Trevino put a 6 wood in the bag? Too much shaft lean made the butter knifes impractical? It seems as though good mechanics and modern lofts are somewhat at odds.

[Mike O]

Couldn't this slight increase in right tricept muscle force also be atributed to extensor action, it is impossible for the right tricept to ever be completly inert as some force must be exterted to creast extensor action to take the slack out of the assembly.

Within the context Jeff's post- I was thinking any comment to right tricep pushing was used in the context of an acceleration force. Certainly, in the context of your post - regarding extensor action there would be right tricep muscle force attributed to extensor action- separate from any pushing acceleration force.

[Jeff]

12PB

You wrote-: "Jeff . . . Homer said that he felt lag pressure so strong that he felt like he could lift himself off the ground . . . BUT he also said that lag pressure is measured out in ounces not pounds. That a pound of lag pressure would be too much to sustain . . . hmmmmmmm . . . . not really sure how to reconcile that."

That's my problem understanding lag pressure and its affect on ball flight distance. Each club needs a different level of forward shaft lean at impact (more for short irons). Therefore, for a given amount of forward clubshaft lean and a given clubhead speed at impact, wouldn't the amount of lag pressure experienced at impact be the same for different swinger-golfers who do not drive load the shaft? How could there be variations in the degree of loss of clubhead forward speed due to impact? How could different golfers have different levels of a "heavy hit" (whatever that means)?

Jeff.

[golfbulldog]

Jeff, the section I quoted from 2-E (6th edition) about zero deceleration was Homer's statement - a theoretical ideal not a practical one... but it does appear that he thought that some resistance to deceleration was possible by maintaining shaft stress through lag pressure.

This may be an area for TGM summit people ?

Perhaps scientifically incorrect but a very real feeling.?? LAG pressure at impact is the way to achieve it...if it is possible to resist deceleration....but then we want lag pressure at impact for other reasons (alignment / stop floipping)....

So stick with lag pressure - let science people worry about impact deceleration - but in the back of your mind accept that HK may have got that that bit incorrect...but he got the big bits right.

[no_mind_golfer]

http://nmgolfscience.tripod.com/img/collisions.gif

That's the pertinent equation shown at that link above. (you'll have to copy/paste it into your browser it seems)

Ma - is the "effective" mass striking the ball (Mb)
e - is the coefficient of restitution
Vo - is clubhead speed before impact
Va - is clubhead speed after impact
Vb - is ball speed after impact

If you drop a ball onto a massive hard surface it will (partially) rebound. The ratio of the height it rebounds to to the height it is dropped from is "e" or COR. COR (coefficient of restitution) accounts for energy lost during deformation.

Normally the club head might weigh .2 kg and the ball 0.046 kg. The governing equation tells us that:

Vb = 0.813 * Vo ( 1 + e )

If you are using a modern high-tech driver then

e = 0.83 and Vb = 1.48 Vo

The question is is there anything a golfer can do to increase the "effective mass" - Ma ? Is there anything a golfer can do to make the .2kg club head look more massive?

---------

Think of a diving board. The diver "jumps" on the "spring board" and it deflects. The diving board is a cantilevered beam which is a kind of spring. The golf club is also like a cantilevered beam. But because of the centripetal loading (which is not insignificant) the golf club is an "axial loaded" cantilevered beam. A beam with axial load is significantly more stiff than an ordinary cantilevered beam. Nevertheless it is still a (relatively flexible) spring.

http://nmgolfscience.tripod.com/img/ballspringch.gif

That link shows a diagram of the situation. If the spring supporting the 0.2 kg club head mass (labeled "beam" in the diagram) were infinitely stiff... then the collisions would be identical to the case where a ball bounces off a hard floor. In that case the governing equation tells us :

Vb = (1 + e ) Vo or Vb = 1.83 Vo

But club shafts being swung by fleshy palms are not infinitely stiff. The and the stiffness of a shaft (spring constant) is set by design parameters at the time of manufacture not what the golfer is or is not doing before, during or after impact.

In Conclusion

The golfer can do nothing to resist CH deceleration. Its set by the ratio of the masses (both club head and ball) and to a much much lesser extent the spring stiffness of the shaft (an axial loaded cantilevered beam).

For all practical purposes Cochran and Stobbs got that one correct.