Four years ago Mizuno set out to do something hard. They were tasked with bringing the brand’s woods up to the same performance levels as the companies most successful weapons, Mizuno’s irons.
For the last three seasons, Mizuno released a new driver every year. The ST-190 driver initiated Mizuno’s ST (Speed Technology) project, the ST-200 then added the Beta Ti face and was Mizuno’s first “Tour Ready” driver. The ST-Z and ST-X then added versatility with the option of two models. The ST220 Series represented a big shift in stability and ball speeds from off-centre strikes. Mizuno feels so good about them that they now plan to move to two-year product cycles.
After multiple iterative developments for stability, sound and spin, for 2023 Mizuno has identified the missing piece to its ball speed equation with the CORTECH Chamber – in its ST-230 Series. The CORTECH Chamber encases a stainless-steel weight with elastomeric TPU, taking stress from the clubface and creating an additional source of energy. At the same time, it locates weight closer to the clubface to reduce spin rates, while contributing to a more solid, powerful sensation at impact.
“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.”
Since 2020 all of Mizuno’s contracted professionals have played and aided in the development of the driver. Maintaining a consistent look at address, while incrementally elevating performance has built trust in Mizuno drivers amongst elite players – from college to the PGA Tour.
The new CORTECH Chamber features in 3 new ST-230 drivers, the ST-Z fairway and hybrid.
ST-Z 230 Driver
A straight bias driver with great stability from off centre hits that’s similar in look and character to the previous ST-Z. The Forged SAT 2041 Beta Ti face is boosted by the CORTECH Chamber to be faster from the face, spin less and deliver an incredible, solid sensation at impact, while the carbon sole plate is now a single piece to allow weight to be pushed to the extremes for overall stability. It offers a modern players’ profile and Quick Switch hosel with 4 degrees of adjustability.
“Tour tests for the ST-Z 230 have all been very consistent,” says Chris Voshall, Mizuno’s Director of Product. “Firstly, an appreciation that the look is familiar at address, then satisfaction at how much better it feels off the face. Ball speeds are up on average 1-3mph with spin rates dropping around 200 rpm.”
Availability: Right Hand – 9.5 and 10.5 degrees
Left hand – 9.5 degrees only
ST-X 230 Driver
A more rounded, deeper profile with weight located closer to the hosel means it’s slightly higher spinning and draw biased for the majority. But it’s also more workable for many elite players (especially in lower lofts). Natural drawers of the ball may find more ball speed from the ST-X. The Forged SAT 2041 Beta Ti face is boosted by the CORTECH Chamber to be faster from the face, spin less and deliver an incredible, solid sensation at impact, while the carbon sole plate is now a single piece to allow weight to be pushed to the extremes for overall stability. The deeper profile aligns square in the neutral settings and the Quick Switch hosel offers 4 degrees of workability.
“The new ST-X 230 is a complex character,” says Chris Voshall. “Although in the higher loft option it’s a higher flying draw biased option, the 9.5 for many of our tour players was more workable and faster from the face. You really need to hit both models before making any judgements on which is likely to work best for you.”
Availability: Right Hand – 9.5, 10.5 and 12 degrees
Left Hand – 10.5 degrees
ST-X PLTNM 230 Driver
A high launching, super lightweight draw biased driver – ideal for slower and moderate swing speeds. The ST-X PLTNM is 30g lighter overall than any possible custom option of the ST-X 230, with a high spec Helium Platinum Shaft and lightweight grip. The Forged SAT 2041 Beta Ti face is boosted by the CORTECH Chamber to be faster from the face, spin less and deliver an incredible, solid sensation at impact, while the carbon sole plate is now a single piece to allow weight to be pushed to the extremes for overall stability. Weight is located closer to the shaft axis to create draw bias and the Quick Switch hosel offers 4 degrees of adjustability.
Availability: Right Hand – 10.5 degrees
ST-Z 230 Fairway Wood
A mid-low spinning, high launching, adjustable fairway wood. Although it was developed hand in hand with Mizuno’s tour advisors, it’s mid-sized and playable for all levels. Utilizing a high energy MAS1C steel face boosted by Mizuno’s CORTECH Chamber, it delivers exceptional ball speeds and powerful, solid sensation at impact. The carbon composite crown offers a low centre of gravity and stability while the expanded front to back weighting delivers consistent launch characteristics. The Quick Switch hosel offers 4 degrees of adjustability.
“The elevated ball of the CORTECH Chamber is a great addition to the ST-Z fairway woods, but the stability might be the real stand-out,” says Chris Voshall. “They feel like they are on tracks through impact.”
Availability: Right Hand – 3 wood (15) and 5 wood (18)
Left hand – 3 wood (15)
ST-Z 230 Hybrid
A mid-low spinning, high launching, adjustable hybrid. Although it was developed hand in hand with Mizuno’s tour advisors, it’s playable for all levels. Utilizing a high energy MAS1C steel face boosted by Mizuno’s CORTECH Chamber, it delivers exceptional ball speeds and powerful, solid sensation at impact. It has a slightly larger, more playable footprint than its predecessor the CLK with waffle crown and thick sole weight engineered to create a low sweet spot and deep centre of gravity for high launch and efficient spin rates.
“The CORTECH Chamber is very effective on the fairway woods and hybrids as it does such a good job of lowering the sweet spot – maintaining ball speeds when you have to pinch one from a tight fairway,” says Chris Voshall.
Availability: Right Hand – 2H (16), 3H (19), 4H (22) and 5H (25)
Left Hand – 3H (19) and 4H (22)
The ST230 Series of drivers and metal woods will be available from February. ST-Z 230 Driver / ST-X 230 Driver / ST-Z 230 Platinum Driver will have an RRP of £499 / €549 and the ST-Z 230 Fairway Woods will retail for £299 / €349 with ST-Z 230 Hybrids available for £279 / €319.