Posted by: skip (piks5@sbcglobal.net) on Mon Dec 10 08:41:53 2007

> > >>> Question for Jack. Does torque take place when one uses an aluminum bat? <<<
> >
> > Hi THG
> > > > Torque: Forces applied from opposing directions that cause and object to rotate about a point. – That is a definition of torque I use in reference to the forces applied through the hands at the bat’s handle that induces angular acceleration of the bat-head.
> >
> > I am curious why you mentioned and aluminum bat in particular.
> >
> > Jack Mankin
>
>
> Jack. In your definition of torque, I am assuming that your answer is YES to my question. (And since yes is your answer, I will go into detail.)
>
> 1. If we assume torque exists, we also have to assume that there is a "whip effect" in which the bat actually bends during the angular acceleration.
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> This bending of the bat bat would make sense and go in line with your argument that a tremendous amount of stress is being put on the bat because of the wrist action involved during THT and BHT.
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> But the question is can stress be put on a bat that is made of maple, hickory, or aluminum? Those type of bats do not have the same bending (spring board) properties as ash. Therefore, how relevent is torque with those type of bats?
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> And if the modern move is to use maple bats over ash, does that mean that the mass and or hardness of the bat is much more relevent than the initiation of torque during the swing?

THG:

Respectable academic research on the net suggests that the "bending" of bats (along their length) is negligible in improving batted ball speed.
This research is from two of the top three bat labs in the country, Sherwood at Umass-Lowell, and Russell at Kettering U. (the third is Smith at WSU).

Russell cites Sherwood's slow-mo studies of thousands of MLB swings. Prof. Sherwood's studies suggest that "... the increase in batted-ball speed gained by accounting for flex in wood and aluminum baseball bats would only be in the amount of 0.4 mph. The research study concluded that whip action did not significantly contribute to final batted-ball speed for wood and aluminum baseball bats and could effectively be ignored."

Check out this link below, and be sure to scroll down to the footage showing an alum. bat bending severely on off-center impacts, AFTER the ball has made contact. As Jack points out, the ball is in contact with the bat for something like a thousandth of a second.

"Do Flexible Handles effect the Performance..." Dan Russell, Phd.
http://www.kettering.edu/~drussell/bats-new/handle-flex.html

The myth of "whip-action" bats may contribute to the faulty notion that the bat acts like a whip--rather than a pendulum--during the course of a swing.


skip