About Face: Mizuno’s New ST Drivers and Fairways

In recent months, manufacturers’ stories advocating the benefits of their driver face’s special properties have become numerous. Mizuno’s new ST drivers continue that trend, but there’s plenty more besides.

By Tony Dear

Mizuno building first-rate drivers isn’t a story any more, right? Time was, not so very long ago in fact, news of a Mizuno driver was viewed with a certain reservation, if not downright skepticism. And as long as it continues building irons like those in the MP-20 Range and JPX 921 Series, the famous Japanese brand will forever be better-known for its irons. But its drivers are no longer token efforts. In the last half-dozen years or so, starting perhaps with the JPX 850 in 2016, and moving into the ST Series, they have not only become definite contenders for a place in your bag, but worthy of the professional Tours too.

Everything has just got better – sound, performance and, most of all, looks. Though the JPX 850 and its successor, the JPX 900, performed admirably they looked…um…awkward. The crown was blue for starters. Some liked it, most didn’t. It wasn’t quite a novelty look, but it contributed to the club being taken less seriously than it probably should have been. And, while the underside of the 850 was more than acceptable, the 900’s sole looked like a complex music monitor station. Clubfitters could navigate their way around, but the typical golfer was somewhat overwhelmed.

The first ST driver – 2018’s ST-180 – had a much cleaner sole, and was the first Mizuno driver to feature Wave technology. But the crown was still blue. Next in line – the ST-190 – was Mizuno’s first black driver in five years and just looked the part. The glossy, carbon crown was both attractive and had significant performance benefits.

Last year’s ST200 and ST200G really hit a high note, especially in the looks department. The sole was the cleanest yet, and the shiny carbon crown just looked sharp. Performance-wise it jumped a notch with a new face – SP700 Titanium made way for Forged SAT 2041 Beta Titanium that was even stronger, lighter, and more flexible and had a successful 20-year history in the pro-cycling arena. It resulted in Mizuno’s highest ever ball speeds.

And now, 12 months later – you’ve noticed Mizuno has been working on a one-year driver cycle for some time now – we have the ST-Z and ST-X. Both drivers feature the same forged SAT 2041 Beta Titanium face (75% Titanium, 20% Vanadium, 4% Aluminum, 1% Tin) that the ST200 owned, but it has been tweaked to ensure the face snaps back into position quicker improving ball speeds, and to make it more resistant to fatigue meaning its Characteristic Time (CT – its springiness) stays within USGA limits for longer.

Every manufacturer seems to be touting a driver face that’s superior to the competition thanks to either Artificial Intelligence or some until-recently unheard of alloy that delivers unprecedented ballspeeds, and likewise Mizuno insists its face is unique. “With an extra year’s experience engineering the Forged Beta SAT2041 Ti, we were able to release a little extra ball speed and ensure a much more satisfying experience off the clubface,” says Mizuno’s Head of Product, Chris Voshall.

It’s not all about the face though. No matter how impressive it is, one notable design feature doesn’t cut it these days – it needs more.

The Wave sole design, which performs much the same task as Titleist’s Active Recoil Channel and TaylorMade’s Speed Pocket, has been refined ultimately resulting in greater Co-efficient of Restitution (COR) and increased ballspeeds. Both drivers feature an adjustable hosel which allows players and fitters to alter the club’s loft by as much as two degrees, up or down.

As for differences between the two drivers, the ST-Z features two carbon composite sections in the sole – one heel-side the other on the toe side – to give up weight which has been taken up by an 11g weight which gives up discretionary weight which is taken up in the 11g weight in the back of the sole. This design ensures the center of Gravity (CG) moves back and low in the head and remains central (Mizuno refers to this face-to-rear axis as the ‘Z-Axis’). This means the ST-Z has no shot bias and sets up neutral.

The ST-X meanwhile, possesses one large carbon panel positioned toward the heel side of clubhead, and the 11g weight is likewise nearer the heel than toe. This results in a draw-bias.

ST-Z Drivers

Lofts – 9.5˚ (right and left-hand), 10.5˚ (right-hand only)
Shafts – Fujikura Motore X, Project X EvenFlow RipTide CB

ST-X Drivers

Lofts – 10.5˚, 12˚
Shafts – Fujikura Motore X, Project X EvenFlow RipTide CB
The lightweight ‘J Spec’ (Japanese Spec) is also available. It is 7g lighter and 0.75” longer than the standard ST-X.

ST-Z Fairway Metals

The ST-Z Fairway Metals features Mizuno’s thinnest MAS1C face yet, a carbon composite crown, a more compact Wave sole to lower the CG and boost Moment of Inertia (MoI), and Quick Switch adjustability allowing you to alter the club’s loft by two degrees, up or down.
Lofts – 15˚ (right and left-hand), 18˚ (right-hand only)
Shafts – Fujikura Motore X F3 7


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