The story on Development of MG702 3 Starting All Over Again--From Scratch
The MG702 prototype that Sato had been working so hard on was lost in an accident the next day before daybreak.
And it was not only Sato’s prototype. A great deal of material from the R&D Department, which is the heart of the Sakata Plant, was lost in a matter of a few hours. Hiroshi Suwa, Department Manager, sobbed uncontrollably in front of all of the plant’s employees, who had been called together for an emergency meeting on that morning. The tears of such a strong man brought on more tears, and all of us made a pledge to strive for a rapid recovery.
There was no longer any way that we could possibly delay the development of the MG702, which was scheduled to go on sale a year later. Springing to life immediately after being so entirely crushed by the accident, Sato set to work on re-producing the prototype. Because the specification sheet had also been lost, he had no choice but to rely on his memory for the numerical data and the design. He loaded the master head with lead--grinding it down with a file to complete the prototype--all with a mere two days of lost time.
The MG702 features a number of factors designed to render its center of gravity lower and deeper, including even greater face progression than that of the MG701, plus a l.5 degree higher loft.
Looking back, Sato describes it as a “battle with weight.” The head weight couldn’t be changed at the point where it had already been determined, so instead we had to alter the center of gravity position. We needed to think about where we could shave a few grams, which spots we could shift a few millimeters—and this is where we could really show off our secret know-how!
First, we made the hosel three millimeters shorter than previously, and we altered the surface area where the shaft and head are joined, which reduced hosel weight by a few grams. In addition, we proposed adding the golf industry’s very first double slit to the heel. After trying various numbers of slits, we concluded that two was the magic number in terms of both design and performance.
With these steps, we shifted the center of gravity to the sole.
The center of gravity height, which runs from the sole to the center of gravity, was rendered lower, while the center of gravity span, which runs from the curve of the shaft to the center of gravity, was crafted longer. These created a higher strike angle and better carry. Also, by making the sole wider in certain parts, we were able to adjust for stability and for the sweet spot. However, a wider sole meant a greater surface area where friction can occur, a potential obstacle to swinging the head all the way through. This is where Sato proposed a slit design for the back of the sole. This reduces the surface area prone to friction, improving the golfer's ability to swing completely and also enabling a shift in weight.
This model has one other special characteristic: the double etching on the cavity. To enable us to adjust the size of the sweet spot, we altered the upper cavity thickness to 1.9 mm and the bottom to 2.3 mm, and also added contrasting etching at top and bottom for a decorative effect. As Sato says, “The MG701 was linear, so I gave the new model a curved-line design.” Though everybody in the R&D Department at Sakata Plant has a terrific sense of style, Sato’s design sense is nothing short of impeccable.