Thursday, April 8, 2010

Are there any "real" improvements yet to be discovered in driver head design? Every year the OEM ads promise more and more distance.

According to Tom Wishon: "The OEM golf equipment industry works in the realm of "tiny" improvements in clubheads, but we here at Tom Wishon Golf Technology don't. How do you define whether a clubhead design improvement is viable or worthwhile? By the marketing claim? By a scientific measurement difference? Or by a golfer hitting shots and being able to visibly or perceptibly notice a difference in the result of the shot?

TWGT lives in the area of the last point. The big companies tend to live in the area of the first two points.

Let's look at driver design to try to see what improvements are possible. . . .

This one's easy. The USGA/R&A have a limit of 0.830 (CT measurement of 257 usecs). In driver design, virtually every company makes their drivers as close to this limit as possible. Every company has to deal with +/- tolerances in all sorts of specs on their driver heads, including the COR. Yes, if you can find a company with a CT measurement machine that is willing to "hand select" a driver head to have its CT right at the 257 limit in the rules, maybe your current driver is somewhere around 239-245 or so. And in that case, you might see about 1 yard, maybe 2 yards more distance. But that's not really a significant design difference - that's more like squeezing a little blood out of the turnip.

This one's interesting for several reasons. First, the USGA for some odd reason chose to set the limit for drivers at 5900 g-cm2 with a +100 g-cm2 tolerance - a limit that no company can reach on a driver that is made to a normal headweight and to a size within the 460cc limit imposed in the rules. Remember the first year after the MOI Rule went into effect?

You had two or three companies marketing drivers they said had an MOI of 5250 g-cm2. Then a year later, NIke said one of their square SQ drivers had an MOI of 5900. Upon closer inspection of this driver, it was made to a swingweight of E2 to E4. In other words, Nike hit that 5900 MOI by simply adding weight to the head, taking advantage of the fact that for each 1 gram you increase the weight of the driver head, you increase the MOI by about 32 g-cm2.

But who on the planet should be playing with a driver with a swingweight in the E range? Few if any. So all NIke did was create something unplayable by the masses simply to be able to market that they hit the MOI limit of the rules. What's more interesting is the fact that since this time, no OEM driver has come out with an MOI higher than 5300 with a normal swingweight.

This is another way of saying that none of the companies have figured out how to make a "reasonably affordable" driver within the rule for size, and within the range of normal headweight, that would be able to have an MOI higher than around 5300.

Could one be made? And if so, how much better would it be? If the driver body is made from something lighter like Aluminum or Magnesium or Graphite and made to be 460cc in size/volume, one could probably attach a bunch of tungsten around the perimeter of the head and possibly get the MOI higher than 5300 while still keeping the headweight within a normal (playable) range.

But such a driver would cost a LOT more than current drivers because of the materials and manufacturing cost to make something like that. And few if any of the OEM companies are ready to try to pin all their marketing hopes on a driver that would have to sell 700,000 units in a year which would retail for around $500-600. Such a price point won't fly in today's market, and the OEMs know that.

But what if price were not an issue? What difference would a golfer note in playing a driver with a 5900 MOI compared to one at 5000 or 5200?

One of the engineering groups we do consulting work for and from which we get some modeling work done did a very carefully constructed FEA modeling project to determine the effect of MOI increases on the amount the head would twist in response to an off center hit.

To make a long story short, they found that for a 3/4" off center hit at 109mph, a driver head with an MOI that would be 1400 g-cm2 higher would see a reduction in twisting of the head of 1/4*. Put this into a more "normal" golfer's hands - by normal golfer I mean a golfer with a 90mph swing speed. Now you are talking about a 1400 g-cm2 increase in MOI bringing about a reduction in twisting more along the line of 1/8*. That's pretty small. Not exactly what you would say would be a very pronounced improvement.

As we have done here at TWGT, we focus more on trying to keep the smash factor high for off center hits by working with the variable thickness design of the face. After we completed the work on the 919THI Driver face, we did a CT test all around the face on one sample 919 head that we were able to create that had a perfect 0.830 COR right in the geometric center of the face. The CT drop off for off center areas of the 919 face was only equivalent to a COR drop of about 0.008 or so. VERY little drop off.

And TWGT is not the only company able to design a variable thickness face that keeps the smash factor pretty high for off center hits. So this means even if a technology came about which allowed the face to be designed to have a perfect 0.830 COR all over the face, the distance improvement for off center hits would be pretty darn small -only on the order of about 2, maybe 3 more yards for a golfer with a 100-110mph swing speed.

So then, what's left after COR, MOI, FACE DESIGN for outright driver head design improvement that a golfer can notice in the first time he goes out to hit the club?

Well for 98+ per cent of all golfers there is professional, full specifications custom fitting. Since about that many golfers have never, ever experienced real custom fitting, that's a pretty strong number of golfers who are sitting on their butts wanting to play better golf, hoping for the next great design technology, while out there under their noses lies the greatest single technology they could ever hope to find for being able to hit the ball better.

As long as there are golfers who hang on every word of the OEM companies and who think the OEM companies are the best club companies on the planet, then there are going to be a lot of golfers who are going to be sorely disappointed.

But on the other hand, if these golfers could somehow open their minds to listen to the facts about fitting, then you could have a TON of golfers who could hit the ball better and enjoy the game more".

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