The story on Development of MG702 2 The “Kurikawa Project” Begins
The fundamental concept for the new iron had been determined: “getting amazing carry by simply hitting the ball.”
The very first step in achieving the best possible carry was to raise the loft. Simulating the difference between “volleying” and “smashing” in tennis, the more perpendicular the impact is to the ball, the better the carry. To achieve the desired result, the new iron featured a 1.5 degree higher loft than the MG701 as its basic design.
In addition, by making the face progression even greater than that of the MG701, we improved the club’s capacity to propel the ball further. This type of structure, which features a curved neck and a head that falls behind the shaft is called a “gooseneck” for the bird that it resembles. It was crafted as straight as possible so that it would hit the ball at roughly the same time as impact.
In itself, however, this design had disadvantages. Even in cases where the ball landed properly due to a low strike angle, it would tend to roll because of restitution from the side. In other words, even where the ball does in fact land on the green, there is a risk of it rolling off. Further, with middle and long irons, even though the structure does produce carry, the strength to send the ball flying high is required of the golfer. In addition, irons with a straight touch are harder to nail the ball with for golfers who tend to have slower head speed on impact. That means the golfer will definitely tend to slice more often.
The question we faced then was how we could achieve carry for the new iron with the same strike angle as the MG701. The lower the center of gravity of the head, the greater the ability of the golfer to hit the ball higher: the same principle as the pendulum. A design to surpass the MG701—itself already an extremely low-center-of-gravity design: Sato called it, “the most difficult challenge of my 20-plus-year career.”
Taking the MG701 and the MG702 in your hands and comparing them, you can get an idea of the essence of Sato’s design…..the slightly short hosel, the smooth arch with a widened sole, the eye-catching slits on the heel, the slim, sleek edge, the double edging on the cavity—a first in the industry—and much more. This all serves to illustrate that the craftsmen’s intuition reaches far beyond the limits of hydrodynamics.
Like an artist heading for his studio, Sato headed for the development office at the plant with sketchbook in hand, working with his clumsily sharpened pencil. The complete blueprint inside his head became a series of lines and surfaces on paper. Sato, very much the artist, could draw the subtle shadings of light and shadow as if the object were right there in front of him.
The next step was to create prototypes for items that Suwa gave the nod to. The MG701 prototype was loaded with lead using a soldering gun, which was filed with a gold file. Careful fine-tuning was done throughout this process. At Honma Golf, we had our very own design method: first make the prototype, next generate a CAD diagram. The advantages of this process are that the design can be inspected right there, and at the same time the intuition of the craftsman—something that cannot be duplicated by a computer—comes alive.
One cold night at the end of winter 2006, after many meetings, trials, and a lot of overtime, Sato at last completed the MG702 prototype.