| Dual Face = Maximum Ball Speed
+ Largest Sweet Spot
By Michael Cheng
Longer drive and larger sweet spot have always been the holy grails in golf. In the earlier days, golf designers manipulated face thickness to enhance its co-efficient of restitution (COR) to produce a longer driving distance. Since the adoption of COR standard by the USGA, meeting its legal limit has become a default standard amongst reputable driver in the market place.
The variable face thickness concept was not invented over night. It was widely known amongst golf designers and top players that by grinding the club face the driving distance can be notably improved. The first invention that bore some resemblance to the current implementation was the patent filed in 1994 by Glenn Schmidt and Richard Helmstetter of Callaway Golf. It called for a gradual increase of vertical thickness from toe and heel toward the center of the club face. This early implementation was simply a way to prevent stress failure of the striking face.
Six years later in 2000, the first contemporary oval shape design that places thicker face behind the sweet spot emerged. It was again pioneered by Callaway. Titleist soon followed. In 2002, Ping filed the first patent on the reversed cone face structure. Not to be left behind, TaylorMade followed up with its own version of it soon after.
There are several schools of thought on the variable face thickness: dome, reversed cone, and x face. They all intend to accomplish the same objective of putting just enough thickness behind the sweet spot to prevent stress failure and less thickness around the rest of the club face. By manipulating the thickness contrast between the sweet spot and the area outside of it, the trampoline effect is maximized.
With COR standardized, golf designers are once again tasked to outdo themselves. The new challenge is to maximize ball speed under the COR limit of 8.30. As a long-time supplier to the long drive circle, I noted over a decade ago that the extent of the club face percussion can be identified by striking the driver face with the edge of a quarter. A sharp and high-pitched sound usually associates with a high percussion.
Based upon our previous patented invention about using a sandwiched titanium structure to improve structural strength that was used in our Titanium Lite and Impulse shafts, I figured that a sandwiched titanium face would naturally be thinner and stronger than a one piece structure as advocated by most golf companies. The best analogy is to compare plywood and solid wood. A piece of properly constructed plywood is stronger than its equivalent in solid wood. This was the origin of the dual face invention, and this concept was granted a patent by the U.S. Patent Office in 1999.
By using a dual face structure, it allows us to create a much larger sweet spot with a much higher ball speed upon impact as compared to the single layer club face structure. You do not need to wait long. This dual face technology will be built into the upcoming Hathaway V4 and V6 inter-changeable drivers to be distributed by Harrison. |
