Dave, Charlie, et al: The USGA has been working on a "field test" for COR for more than a year because they do want to be able to show up and do spot testing, or even total tournament field testing in this area. And when that happens it is going to be really interesting because most of you guys know how sensitive COR testing can be, as well as how little of a change in one woodhead vs another can make a significant change in the COR. Some weeks back I went through this on one of my new models - the two foundries I will only use for making my Ti woodheads both have the same exact COR testing machinery and perform the test the same way as described and provided by the USGA. This one sample I sent in came to me from our foundry with test data report sheets that said it had a COR of 0.826. I sent it on to the USGA and weeks later they came back and said that it failed the COR test because it was an 0.836. Yet one of the other drivers I sent in came out of the same foundry's COR testing at 0.823 and I got a letter back on this one saying it was conforming. Trying to track down the variables in such a matter is virtually impossible in terms of the time and expense required because there can be so many that all added together could explain the difference when you are trying to get within 0.001 COR points.
So who's right? Well because they make the rules, the public would say the USGA is right. But I also know the technical acumen of my foundry guys too, and they are pretty serious and smart too in these areas. So what they force me to do is to make another head that I test at our foundry and see that it comes in at 0.819 or less so that I can get this ONE head they require under the USGA test. I know my intent is not to make a non-conforming head, but the USGA doesn't. They are aware that there are companies in the business who "specially make" the one head that is required for their testing, but then the company orders the foundry to make the production of all the heads they will sell to be over the limit. And when field testing hits on tour, the media is going to have a field day with it because undoubtedly there will be drivers found in players' bags which will be over the limit. And when the media writes about it the way you know they will, there will be people who will virtually accuse those players of "cheating". Is the field test 100% compatible with the lab testing? I seriously doubt it could be, because you guys who are engineers and tech career people know how hard that would be to do, week after week. Hearing about guys who sand the faces of their drivers is no different than the stories we have all heard over the years that we just need to smirk and chuckle about - up there with secretly rubbing the driver face with chap-stick or pitchers with a rough edge on their belt buckle who try to scuff the baseball during a game. In the case of the COR matter itself that brings about the thought of golfers with sandpaper in their golf bags, it's not the player who should be criticized - it's the organization that did not listen to real science and realize that a COR limit was never needed in the first place. I mean heck, look at all the money the USGA could have saved and donated to junior golf programs if they would have just opened their minds to look at ALL the data about this. OK< stick a fork in me. . I'm done. TOM W -----Original Message----- From: Dave Tutelman [mailto:[EMAIL PROTECTED]] Sent: Tuesday, January 28, 2003 7:41 AM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: Re: ShopTalk: Face Milling At 07:21 AM 1/28/03 -0500, [EMAIL PROTECTED] wrote: >Arnie > I have to disagree with you as far as it doesn't due anything. If are > able to measure ball measure ball velocity before and after the procedure > you will definitely see an increase in ball speed. I forgot what the > distance increase is per 1 mph increase but to tour pros every yard of > carry is significant. Face thickness can be measured but the equipment > costs a couple of thousand dollars. A friend of mine has it and I have > been doing it for a few years. As far as being legal you have to maintain > the .83 COR. > > Charlie My problem with all this is Charlie's last point about being legal. Face grinding attacks the whole structure of golf club conformance enforcement. Golf club conformance is based on "type testing". The USGA (and tournament staffs) do not test every club at every [important] event. They test a small sample (probably a sample of one) of the model from the manufacturer. This is based on an assumption that modifying the head is difficult to do, and especially difficult to do undetectably. If people start modifying the COR of the clubheads with milling machines or grinders, then the whole notion of type testing goes out the window. Clubs will have to be measured at every significant tournament. And, as Charlie notes, it is expensive to measure face thickness. Moreover, there isn't a simple mathematical relationship between face thickness and COR. So the USGA and the PGA tour may have to carry around an air cannon to their events and measure COR directly every time. This is not an idea I'm inventing on the fly. When I raced sailboats, I was also a fleet measurer in the Albacore class (15-foot planing sloop), was on the specifications committee, and was on the national championship measuring staff a few times. At the national championships, all boats were measured before the regatta, in any dimension that was: * Changeable from the original type test. (The hull molds were approved by the class before Albacores could be manufactured from them, so overall size and shape of hull was OK by type testing. That was all that was type tested.) * Affected performance. For lesser regattas than the nationals, there were spot check measurements for one or two dimensions on all boats. Things that were checked included position of the centerboard pivot, ALL controlling dimensions of sails, overall weight of the boat, critical dimensions of spars (mast and boom), and a few other dimensions. We often found transgressions that had to be corrected before you could race. If you arrived a day early for measuring, you had a chance to fix things up. If you showed up the morning of the race with an outaspec boat, you were SOL. (Well, the technical term is DSQ, but SOL is so much more colorful.) I'd hate to see this happen to golf. But I see two trends pushing in that direction: (1) Milling the head to increase COR. This is just begging for a rule to disallow clubs that show visible tampering. Mill or sand the face so it looks different from the head as manufactured, and the club is automatically illegal. (In the days of wooden heads, I'd scream bloody murder about such a rule; I modified clubfaces all the time. BUT... such mods did not affect the COR, or any other rule-based item.) (2) The USGA is about to bring one on itself: the overall length rule. This is something that EVERYBODY changes. If you put a rule on it, you will HAVE TO measure every club at every tournament for conformance. Yecchh! DaveT
