Mizuno’s new range of ST-230 metalwoods, which go on sale next month, boasts a new energy transfer technology which the company says completes the story of the ‘Speed Technology’ project that it has been developing over the past four years.
The ST-190 driver, launched in 2019, was the club that initiated Mizuno’s Speed Technology project, the ST-200 (2020) then added the Beta Ti face and was Mizuno’s first ‘Tour ready’ driver. The ST-Z and ST-X (2021) then added versatility with the option of two models, while the ST220 Series (2022) represented a big shift in stability and ball speeds from off-centre strikes.
This latest range of woods and hybrids – the ST-230 Series – features what Mizuno is calling ‘the missing piece to its ball speed equation’ with the introduction of the CORTECH Chamber. Featuring in the three ST-230 driver models, the ST-Z fairway and ST-Z hybrid, 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.”
ST-Z 230 Driver
The ST-Z 230 is straight-hitting driver with great stability from off-centre hits that is similar in both look and character to the previous ST-Z. The forged Beta Ti face is boosted by the CORTECH Chamber to be faster from the face, spin less and deliver a 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 features 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.”
Loft options: 9.5° (RH/LH), 10.5° (RH only). RRP: £499
ST-X 230 Driver
The ST-X 230 boasts a more rounded, deeper profile than the ST-Z, with weight located closer to the hosel, which means it is slightly higher spinning and draw-biased for the majority of golfers. But it’s also more workable for many elite players, especially in the lower lofts.
It also features the CORTECH chamber, with its associated benefits, while 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.”
Loft options: 9.5°, 10.5°, 12°. RRP: £499
ST-X PLTNM 230 Driver
The ST-X PLATNM is a high-launching, super lightweight, draw-biased driver which is ideal for slower and moderate swing speeds. Up to 30g lighter than any possible custom option of the ST-X 230, the PLTNM is fitted with a high-spec Helium Platinum shaft and lightweight grip.
The Forged 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.
Loft option: 10.5° RRP: £499
ST-Z 230 Fairway Wood
A mid-low spinning, high launching, adjustable fairway wood, the ST-Z offers a mid-sized head and is playable for all levels of golfer.
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: 3 (15°), 5 (18°)
ST-Z 230 Hybrid
A mid-low spinning, high launching, adjustable hybrid, the ST-Z model utilizes a high energy MAS1C steel face boosted by Mizuno’s CORTECH Chamber to 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 Voshall.
Availability: 2 (16°), 3 (19°), 4 (22°) and 5 (25°) RRP: £279
For more details and to find your nearest Mizuno stockist and specialist fitting centre, visit mizunogolf.com