Mizuno after a four-year development process has announced the ST-230 drivers, fairway woods and hybrids including a stainless-steel urethane covered sole weight located just behind the face called the Cortech Chamber.
Fast Facts Mizuno ST-230 Drivers
Forged SAT 2041 beta titanium face
Cortech Chamber sole weight
Carbon fiber crown
Carbon fiber sole plate
Adjustable hosel +/- 2°
Stock grip: Lamkin Hybrid ST
At retail Feb.
Mizuno ST-Z 230 driver
Better player category
14-gram rear sole weight
Straight flight bias
Eight stock shaft options
Mizuno ST-X 230 driver
14-gram heel sole weight
Six stock shaft options
Mizuno ST-X PLTNM 230
Super game-improvement category
7-gram rear sole weight
Stock shaft: HeLIUM PLTNM 40 F2
Mizuno’s story for their latest club family is the Cortech Chamber which they tell us is the “missing piece” and it’s a “new energy source” which translated means more hit on the ball and more distance.
The Cortech Chamber is essentially a very large sole slot behind the face filled with urethane containing a stainless-steel weight. This design both allows the face additional flex at impact and therefore more rebound but also places a significant steel mass close to the face and that promotes lower spin rates. The sole plate is also a new construction being a single piece rather than the previous build of multiple pieces.
The ST-X PLTNM is a first for Mizuno, an ultralight driver for slower swingers such as seniors with an extra long shaft to help with clubhead speed.
Following the general trend for increases prices across the entire club business Mizuno has priced the ST-230 drivers $50 higher than last year’s models.
“Our player testing over the years shows that placing extra weight close to the face results in faster ball speeds and low spin rates,” says David Llewellyn, Director of R&D for Mizuno. “We’ve been steadily working towards the CORTECH Chamber, which is incredibly effective at that job. Encasing the steel weight within the TPU Chamber means that we’re moving weight close to the face at the same time as creating an additional source of energy. Steel is twice the density of Titanium but won’t weld directly, which is where the TPU has a second role.”