As a FYI, 1 of the chapters in Jorgenson's book notes that possibly a better club set would be one that matches in Swing Weight, MOI and Total weight. He nuts out how to do this. If you want to get real specific on the measurements (he recommends a "Looser fit"), he notes backweighting as the methodology to assure consistent total weight. (Actually the weight is location under the hands and not specifically at the butt of the shaft).
Mark A Patton [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Don M Sent: Tuesday, August 15, 2006 2:10 PM To: [email protected] Subject: RE: ShopTalk: Backweighting --- Dave Tutelman <[EMAIL PROTECTED]> wrote: > What is your belief based on? I'm not baiting you, > I'd simply like to know. > :-) Fair enough. It's just a gut feeling. I guess it's based on the fact that even among good golfers, a specification or feature that helps or is liked by one golfer, hurts or is disliked by another. The human element seems to play such a huge role that attempts to reduce it to science seem to me to come up short. In other words, it seems there is as much art as science involved. Like backweighting. You say, I assume correctly, that current physics models don't show much affect from backweighting. Yet some golfers love it. Thanks for your concise explanation of the models. That helps. -Don M > > Seriously... > The golf swing MUST be capable of modeling with > physics. I don't know > anybody personally who has ever said that golf clubs > follow a > different set of laws from everything else in the > universe. The only > issue is how complex the physical model needs to get > before it > reflects the important things in a golf swing. > > Around 1990, Ted Jorgensen did an extensive study > that resulted in > his book, "The Physics of Golf". He was Professor > Emeritus of Physics > at the U of Nebraska. (He died this year.) While the > book covers a > number of very interesting topics, his major > contribution was > creating a physical model of the swing that agreed > with measurement > taken from a real golfer. > > A good golfer was intrumented with reflective dots > at the joints and > at important stations on the golf club, and his > swing recorded with > strobe flash. Then Jorgensen started with the > simplest physical model > (the double-pendulum described by Cochran & Stobbs > -- probably known > well before that), and tried to match the model's > behavior with that > of the measured golf swing. He had to add complexity > to the model > quite a few times before he had a good match. But he > DID get a match that: > * Mirrored pretty much all the recorded golf > club behaviors > during the downswing. > * Accounted for observed changes in performance > resulting from > changes in the parameters of the model (e.g.- > addition of wrist > torque in various points of the swing, head movement > during the swing, etc). > > So I'm fairly confident that Jorgensen's model is > quite capable of > reflecting the sort of gross behavior that > backweighting would > affect. And Max's program is a mechanization of > Jorgensen's model. > > Cheers! > DaveT > > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.0.405 / Virus Database: 268.10.10/418 - > Release Date: 8/14/2006 > > > -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.405 / Virus Database: 268.10.10/419 - Release Date: 8/15/2006 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.405 / Virus Database: 268.10.10/419 - Release Date: 8/15/2006
