After refocusing its approach to metalwood design in recent years, Mizuno has established itself as a force in the driver manufacturing space – both at retail and on professional tours. What was previously known as mostly an iron-making company is now a realistic driver option for golfers across the handicap spectrum.
Mizuno’s previous ST-Z (made for low spin) and ST-X (made for draw spin) driver designs helped golfers find the speed, look and feel they wanted by using a new SAT2041 Beta Ti face, and carbon composite materials in the crown and sole. The only problem, by the company’s own admission, was keeping up the high ball speeds on off-center hits.
In other words, the ST-Z and ST-X drivers were fast, but they had room for improvement when it came to forgiveness.
“By early 2021, with the vast majority of tour players we tested, the ST Series drivers were able to improve on their current driver for ball speed, looks and feel,” says Mizuno’s Director of Product Chris Voshall. “The occasional barrier to getting a driver in play was the distance drop off from off-center strikes.”
Mizuno used real player feedback to help identify the issues, and got to work on making a more forgiving driver that didn’t give up any speed on center strikes. Now, the company has announced its new Mizuno ST-Z 220 and ST-X 220 drivers, which are more forgiving versions of its previous models.
To help achieve higher ball speeds across the face, Mizuno expanded the carbon composite area in the sole by 40 percent and thinned out the titanium portion. By lightening up the crown, that freed up engineers to create a back sole weight that’s double the weight of the previous iterations; it nows weighs in at 20 grams.
These changes allowed Mizuno to drastically increase weight low and rearward in the heads, thus creating a driver that’s more stable at impact.
“Any twisting or deflecting at impact due to an off-center hit is an energy loss and varies launch conditions,” says Mizuno’s Director of R&D David Llewellyn. “By working with the prior ST driver platform and familiar materials, we were able to find several adaptations to impact the internal weighting. Creating far more stable tendencies in both the ST-Z and ST-X.”
Both of the ST-Z 220 drivers and ST-X 220 drivers still come with a fast SAT2041 Beta Ti face, which, according to Mizuno, is made of Super Alloy Titanium, 20 percent Vanadium, 4 percent aluminum, 1 percent tin, and it has 17 percent more tensile strength than traditional 6-4Ti and 8 percent more flexibility. The face construction also features Mizuno’s multi-thickness Cortech design that helps raise speeds where necessary.
The two models use Mizuno’s Wave Sole design on the sole near the face to further increase ball speed, especially low on the face, and Harmonic Impact Research has helped the company reduce vibrations to enhance sound and feel.
The ST-Z 220 and ST-X 220 each measure 460cc, and will sell for $449.95 apiece starting on February 3, 2022.
So, what are the differences between the two models? It’s important to remember that each of the two new models (and Mizuno’s current ST-G 220 driver) are made for golfers with different needs and preferences. The Mizuno ST-G 220 is made for the ultimate adjustability, while the new ST-Z 220 is made for a neutral ball flight and low spin, and the new ST-X 220 is made for a draw spin to reduce a slice.
Mizuno’s ST-Z 220 driver, specifically, has a central back weight that’s balanced between the toe and heel; the weight exists along the Z-axis of the driver. That means it will help provide a neutral ball flight bias, while still dragging weight rearward for greater forgiveness.
“The ST-Z is the most played of all our drivers,” Voshall says. “It’s a modern driver for players who have grown up hitting long straight bombs rather than shaping the ball. The addition of a 20g back weight also makes it an exceptionally forgiving option.”
The ST-Z 220 comes in 9.5 and 10.5 degree options (9.5 degrees only in lefty), and it has a more “ground-hugging” profile that appeals to better players, according to Mizuno.
The ST-X 220 driver, on the other hand, has a more rounded profile that’s meant to produce higher ball flights and more spin. The ST-X also has the 20-gram back weight in a more heel-ward position (on the X-axis) in order to help the face release faster and influence a draw ball flight.
“For a lot of golfers, the modern low spinning driver design preferred by tour players is a serious distance killer,” says Voshall. “The ST-X’s extra spin, slight draw bias and a higher flight will add driving distance for a surprising number of players.”
For additional assistance on speed, the ST-X 220 (10.5 and 12 degrees) is also available in a “J-spec” option, which means it’s equipped with a lighter weight HeLIUM NanoCore shaft that’s best for slower swing speeds.
To fill out the ST-X metalwood family, there are also ST-X 220 fairway woods and hybrids.
The ST-X 220 fairway woods are also made for a high-draw flight with a back weight in the heel portion. The large 3-wood option has a full titanium construction and a SAT2041 Beta face, while the more compact 5 and 7-woods are made with Maraging MAS1C steel faces; the smaller-sized 5 and 7 woods are created with smaller profiles to help with performance from the turf.
Overall, according to Voshall, the fairway woods (16, 18.5 and 21.5 degrees) are made for high launch, helping golfers achieve more height on their shots from the fairway.
“There are a lot of forgiving looking fairways woods that don’t launch high enough for the average amateur,” says Chris Voshall. “Size and footprint is only one part of the equation – most of us need a little more spin and elevation to carry the ball to our full capability. The ST-X is designed to solve that issue.”
