Gear: Mizuno ST-Z, ST-X drivers
Price: $399.99 with Fujikura Motore X or Project X EvenFlow RipTide CB shaft and Lamkin ST Hybrid 360 grip
Specs: Titanium chassis with carbon-fiber crown
Available: February
Mizuno has focused for several years on its iron business, and it developed a reputation for making some of the finest irons in the game. However, starting a few years ago, Mizuno began an initiative to grow its driver presence, concentrating on woods that deliver more distance and increased forgiveness. With the release of the new ST-Z and ST-X drivers, the company is confident it has two drivers that will provide that to a large number of players.
To help golfers generate more ball speed, Mizuno gave both the ST-Z and ST-X drivers a forged SAT2041 Beta titanium face. The company said it is extremely strong but light, making an ideal hitting surface. Mizuno also said it has a higher strain recovery rate, which for non-mechanical engineers means it snaps back into shape faster than other titanium alloys, so the hitting area should flex more efficiently. Finally, Mizuno also found the SAT2041 Beta titanium resists fatigue better. That means as a driver’s life goes on, the characteristic time (the springiness of the face) will not creep over the USGA and R&A’s legal limit.
Both drivers have an adjustable hosel that allows players and fitters to increase or decrease the stated loft by as many as 2 degrees, as well as a lightweight carbon-fiber crown. Internal reinforcements help create a richer, more-dense sound that accomplished players told Mizuno they prefer.
Mizuno designed two carbon-fiber panels into the ST-Z driver’s sole, with one in the heel area and one in the toe. They create more discretionary weight, with much of that repositioned into an 11-gram weight in the sole’s back. That weight helps boost the moment of inertia and increase stability.
Designers worked to position the center of gravity in the ST-Z driver low but on the head’s centerline. (Engineers refer to the left-right center of gravity as the Z axis.) This should give the ST-Z a neutral shot-shaping bias and allow accomplished golfers to hit either draws or fades more easily.
The ST-X driver has a single, large carbon-fiber panel in the toe portion of the sole which wraps into the center area. Its 11-gram weight also was shifted toward the back-heel area. Those two design elements move the center of gravity more toward the heel and create a draw bias for golfers who battle excessive sidespin and a slice.
For slower-swinging players who want the lightest driver possible and who are looking for more carry distance, Mizuno is offering the ST-X J driver. Instead of the 11-gram weight coming standard in the heel, the ST-X J has a 4-gram weight in the sole, and it comes standard at 45.75 inches long, which is .75 inches longer than both the ST-Z and standard ST-X.
