- Mizuno is launching two new ST-series drivers.
- The ST-X offers draw bias with some forgiveness.
- The ST-Z is a low- to mid-spin driver with higher MOI.
- Retail price is $400.
With the launch of the Mizuno ST-X and ST-Z drivers, the company hopes to build on the momentum from its previous ST releases while making its case that it belongs in the conversation with the top-selling driver brands in golf.
New Rules
In past Mizuno stories, we’ve discussed how and why the company’s drivers disappeared from the PGA TOUR. When its competitors began buying Tour counts, notoriously frugal Mizuno grew comfortable with its Tour ambassadors not playing its drivers. The approach was to give its staffers plenty of time to work their way into Mizuno driver. More often than not, they never did and the company never said much about it.
For more than a decade, the count of Mizuno drivers in play on the Tour held steady at zero.
Over the past couple of seasons, things have changed. The company has rolled out a fresh approach—a new rulebook of sorts. Like many of its competitors, Mizuno has become increasingly rigid about staffers bagging its drivers. Potential new Tour signings are advised to be absolutely sure the driver is going to work.
As Tour player feedback has played a more significant role in designs like the ST-X and ST-Z, Mizuno’s Tour counts have ticked up, though admittedly “up” was the only mathematically viable option.
Along the way, you may have noticed that Mizuno has accelerated its design process. Iteration is now on the clock with one year becoming the standard cycle for the once more conservative brand. Average golfers—at least those who pay attention—love longer cycles but for Mizuno the extra time became a liability. If a Tour player didn’t like the driver, Mizuno had to wait 1.5 years to try again.
Not exactly a recipe for Tour success. And so, one year removed from ST-200, here we are. The company believes enough advancements have been made that the time for talking is over. If you want to take that to mean that ST is short for Show Time, that’s reasonable enough.
Mizuno ST-X and ST-Z Drivers
Mizuno’s latest one-year-cycle drivers are the ST-X and the ST-Z. Some of you may immediately notice the absence of a low-spin, movable-weight ST-G. The G is sitting out this release cycle but that doesn’t mean it won’t be back.
The X and Z names speak to the distribution of mass within the clubhead. With the ST-X, mass is pushed along the X-axis towards the heel, providing draw bias.
With the ST-Z, mass is pushed along the Z-axis, low and towards the back of the club. The idea is to increase forgiveness while keeping spin under control.
Mizuno’s big picture goals for the ST-X and ST-Z were pretty straightforward: take what was good with the ST-200 and build on it. Evolve the technology, show gains and, while we’re at it, improve the looks, sound and feel of the drivers.
Here’s what Mizuno did in pursuit of those goals.
CORTECH Beta Titanium Face
2021 is shaping up to be the year of the driver face. That’s always true to some degree but this year, more than any other in recent memory, the face is the thing brands are pointing to as the source of speed.
In the case of the Mizuno ST-X and ST-Z drivers, the material itself hasn’t changed from the previous generation. Mizuno is still using Forged SAT 2041 Beta Titanium. Mizuno believes the material is superior to anything its competitors are using.
“Everybody has their material story that’s better than everything else,” says Mizuno’s Chris Voshall. “We have that and more.”
Voshall points specifically to Beta Titanium’s higher strain rate recovery and finer grain structure. The first means the material returns to its shape faster, promoting incremental ball speed gains. The second one means the material is less prone to fatigue which ultimately means greater durability and, more importantly, less CT creep (speed of the face increasing over time).
Mizuno did some reengineering of its driver face topology, strategically thinning an area in the lower portion of the face to boost speed on low face contact but, like most of its competitors, a portion of the speed story comes from tighter tolerances.
As Mizuno has become more familiar with SAT 2041, it has gained a better understanding of how far it can safely push its design targets while still providing consistent parts that conform to USGA rules. One of the easiest ways to gain ball speed is to design to raise your CT targets.
When you have your head fully wrapped around the capabilities of your face material, you can do exactly that.
WAVE Feature Optimization
A signature feature of its metalwoods for the past several generations, both the Mizuno ST-X and Mizuno ST-Z drivers feature a WAVE sole design.
The purpose of the Wave sole is to remove stress on the face by absorbing some of the deflection in the low area of the clubface. Functionally, it’s similar to TaylorMade’s Speed Pocket or Titleist’s Active Recoil Channel. Mizuno says that leads to a larger COR Area (the portion of the face that provides near-max ball speed).
CT Rib structures
I suppose you could say the CT rib structures connecting the top of the Mizuno ST-X and ST-Z driver faces are the top of the heads complement to the WAVE Sole. The features serve to expand the COR area and provide increased durability while ensuring the CT remains within legal limits.
With the three technologies (CORTECH face, WAVE sole and CT Ribs) found in the ST-X and ST-Z, Mizuno is trying to gain speed by taking advantage of the lack of absolute correlation between COR (the USGA’s old standard for governing driver speed) and CT (the current standard).
There’s near-universal agreement that, within that space, there is an opportunity to push speed beyond what the old rule would have allowed for while still remaining under the current limit.
We’re not talking huge gains but there is room for incremental improvement as materials evolve and manufacturing advances allow for more complex geometries to be produced.
Refined Aesthetics
Filed under “aesthetic refinements,” Mizuno has updated the look of its carbon fiber crown. While the entire crown is gloss black, a large portion of it features a visible carbon weave pattern. A broad leading edge surrounds the weave pattern.
The carbon fiber elements on the sole also show off the weave. It’s a small detail but, in one man’s opinion, it makes for a more refined and visually appealing design overall.
With the commonalities covered, let’s look at the individual model details.
ST-X Driver
The Mizuno ST-X is the company’s entry into the draw-bias space. Mizuno understands that draw bias isn’t for everyone (it’s part of the reason why it makes more than one driver) but it’s also hoping golfers will be open-minded about fitting.
The ST-200X got a fair amount of play among Mizuno’s female roster and there’s reason to believe average golfers could benefit as well. The company’s approach is to provide the draw bias many golfers need without trading away all of the forgiveness.
ST-X Driver – Not exclusively long and light
Where the Mizuno ST-X driver differs from the previous model is that it isn’t built to J Spec (Japanese Specification). Unless you want it to be, that is.
J Spec remains an option but it’s not the only option. That speaks to Mizuno’s desire not to pigeonhole the ST-X driver as something exclusively for 70-year-olds.
This time around, the standard ST-X driver is 45 inches with an 11-gram weight screw and a total head weight of 204 grams.
The lightweight and long J Spec version is 45.75 inches with a four-gram weight screw and a total head weight of 194 grams.
Basically, the Mizuno ST-X driver is what you want it to be, which is how it should be.
The Mizuno ST-X driver is available in 10.5 and 12 degrees.
Stock shafts in the standard ST-X driver include the Fujikura Motore X F3 and the Project X EvenFlow Riptide CB (both “real-deal”). The stock shaft in the J Spec version of the ST-X is Mizuno’s M Fusion 40.
Mizuno ST-Z Driver
The Mizuno ST-Z driver is the company’s middle-of-the-market entry. It’s a higher MOI (forgiveness) head designed to produces low to mid spin by keeping the center of gravity close to the neutral axis.
The Mizuno ST-Z is described as offering forgiveness with low spin which is an increasingly common designation within the market place.
Mizuno says the ST-Z driver has a neutral bias (no predisposition to draws or fades). The weight screw is centrally located and instead of a single carbon-fiber sole piece like the one in the ST-X, the ST-Z driver offers two carbon-fiber sole plates balanced on either side of center.
The Mizuno ST-Z driver is available in 9.5 and 10.5 degrees. The 10.5 model is available in RH only. The stock length is 45 inches.
Pricing and Availability
The Mizuno ST-X and ST-Z drivers are $400. Retail availability begins Feb. 18. For more information, visit Mizunousa.com.
Matt
2 years agoI will play Mizuno irons as long as I still play golf. They are well made and have something for everyone.
The best part about Mizuno is they have a ton of free shaft options from a variety of makers. You didn’t have to break the bank getting proper shafts. I hope they do the same for the drivers.
All that being sad, it would really have to outperform a PING G400-425 or a Taylormade SIM for me to trust the drivers/woods.
Andy P
2 years agoHi
So yesterday I had a fitting at my local range. I had an old M2 driver and needed an upgrade. I tried everything Sim 2, TSi, ZX7, G425, Cobra and the Mizuno STZ & X.
Dont get me wrong all of them were very very good drivers but the look and the feel of the mizuno in my eyes was something else.
I was fitted on trackman and on the day my swing speed was 101mph (usually a bit faster but I had a few layers on due to it being -1 outside) and on the optimiser it said that I should be hitting around 151 ball speed with a carry of around 260.
Sim 2 – average ball speed I got was 148 and 245 carry
TSI3 – average speed 149 carry 252
G425 Max – average ball speed 148 carry 255
Cobra – average ball speed 146 carry 249
Mizuno STX – average ball speed 151 carry 261
MIZUNO STZ – AVERAGE BALL SPEED 153 carry 266
The difference in the flight and launch was noticeable for me. I managed to find the correct shaft and head combination with the STZ which meant that I had found the perfect club especially with the dispersion I got.
So I got the STZ with the atmos blue 6s shaft and only paid £320 compared to the others which were all over the £400
100% have a go with the STZ.
When I was there I also tried the STZ fairway which I have to say is the easiest launching and forgiving fairway I have ever tried. Absolutely amazing clubs.
Ian
2 years agoWhy would anybody want ‘less CT creep’?
Tony Covey
2 years agoYou’re really only going to design a driver one way (one face material) and if your products get used on TOUR, you simply can’t have CT creep. It was a huge issue a couple years with Xander’s and other drivers tested by the USGA coming back over the limit.. With the CT test, OEMs have to account for what amounts to tolerances within tolerance within tolerances, so the right approach is to set the target as high as you can safely hit and use materials that don’t creep.
Max R
2 years agoI watched the most recent NPG Episode and once again, found it entertaining, honest and very informative. Good to see Adam contributing again.
I have a comment regarding Mizuno’s new iteration of drivers. I have the ST190 and have played it for 2 years. I was fitted for a number of different manufacturers, shafts, lies, etc.. and the ST190 was the best for me.
Yes, Mizuno has only recently improved its direction in developing/manufacturing drivers with the same conviction of their irons. Yes, there’s a gap between them and the Big Five. However, the room to grow for Mizuno exceeds the microscopic steps that remain for the Big Five provided that USGA tolerances don’t significantly change in the near future. So, Mizuno and Chris Voshall have room to grow with a bright future ahead. Will try to switch my ST190 head with the STz and check the difference between the two.
GREG
2 years agoI’ve given up on Mizuno drivers. All hype with a 2 cylinder engine under the bonnet. – so to speak. Over two years ago I switched from Mizuno to Epon with the driver and haven’t had a moment’s regret – consistently hit it 30 yards longer. Epon’s new EF-01 is even longer than their previous AF-105. No problems when you trade Epon gear – there are always buyers.
Jack B.
2 years agoThanks for the review. Very attractive clubheads, although I prefer the face to have the normal metallic color.
I’m curious about Japan spec. I assume that means clubs built shorter for shorter people. Is there more to it than that?
Also, are you sure there’s not a mistake in this paragraph?
“Voshall points specifically to Beta Titanium’s higher strain rate recovery and finer grain structure. The first means the material returns to its shape faster, promoting incremental ball speed gains. The second one means the material is less prone to fatigue which ultimately means greater durability and, more importantly, less CT creep (speed of the face increasing over time).”
AL
2 years agoThe J-spec as noted in the article is longer (45.75 inches), has less weight (10 grams less head weight) and has a lighter shaft.
Max R
2 years agoLove my ST190! Got fitted by Mizuno and after a number of shaft and lie changes we finally settled on what works best for me. I should mention that I spent a significant amount of time (and money) trying out other drivers/shafts/lies from their competitors. It was worth it. The only thing I wish that was available with Mizuno (and other manufacturers) is a shaft adapter for complement Golf Pride’s Align Grip. Once, you change the loft/lie of the driver the grip’s Align and feel are lost.
Kevin
2 years agoThey review well, come from a company with a great reputation and are priced great. 3 out of 4. I won’t buy a club I can’t demo first to see if it works with my swing. I would love to try Mizuno but have a hard time finding a local shop that stocks and demos them.
Richard
2 years agoPGA Tour SuperStore carries the heads and a good variety of the available shafts. Some (not all) Golf Galaxies also have demos. I find Mizunos go a bit to the right, which is great with my miss going hard left. Good variety of no upcharge shafts.
Walter
2 years agoNice to see Mizuno doing more in the driver space and keeping the prices low, but that puts them in the same pricing as Tour Edge and TE makes a pretty driver now. So can they compete with TE.
John
2 years agoI had an MP630 driver back in the day. Loved it for a while before moving on. It performed well and looked classically classy. In recent times I had an ST180 for a much shorter while. Lost a good bit of distance with a non-commensurate improvement in accuracy. These drivers will need to seriously perform in the Most Wanted test if they are to be considered by golfers. Mizuno seem to go at the driver space one in every four releases or so. It seems like they don’t want to sacrifice R&D on drivers when their irons is what puts food on their table. I think this release might perform good (the 1 in 4). Mostly their releases just fall back into the pack and get lost in the noise.
Daniel D Balint
2 years agoYes, I have been a fan of Mizuno for years. Will they offer shafts in a Senior flex? My clubhead speed is about 80 MPH.
Thanks
Bill from Florida
2 years agoMizuno will offer 50 NO Up-Charge shafts for the new 2021 drivers. There are many available in SR flex.
Joe Golfer
2 years agoWow. That’s a lot of shaft options with no upcharge.
Matt
2 years agoThe Mizuno website only lists 36 no-upcharge shafts. What’s your source for them offering 50?
Mark
2 years agoWhen tour players without club deals start playing the Mizuno drivers, I’ll start to take an interest. Until then, I’ll keep my trusted M2 in play.
My opinion is the slight changes in face design are minimal for most golfers. Getting fitted to the correct shaft will provide the greatest distance gain – that’s the engine of the club..
MyGolfSpy should focus some time on shafts,
Joe
2 years agoThe Mizuno ST190 blew the socks off of my M2. People with Sims look at my driver like what the hell is that you hit. Consistantly smashing straight drives is pure joy. I’m 64 years old and am quite fond of fairways. I did switch from Mizuno blades to P790’s. I don’t care what pro’s play. I do care about how I play. I’m getting fitted for the new ST. The confidence reflects on the rest of my game. The ST 3 wood is the best I’ve played. XXIO X 3hybrid stiff. 5-A P790. Vokey wedges. Bettinardi putter. Other than the new Mizuno driver. I’m staying put.
McaseyM
2 years agoI’m looking forward to trying these out. Very nice refinements on styling. Seems to be good price point coming in $130 less than TM or Callaway, but will have to check shaft options. Can’t wait to see how these perform in Most Wanted testing.
WiTerp50
2 years agoGood review short of actual testing data. My personal issue is with the author’s reference to the X “pigeon-holed” to 70 year olds.” Unneeded and disrespectful not to just 70 self, but other diminutive/handicapped members of society for which we appreciate vendors including us in the marketing, even though the MySpy group is biased as wannabe pro’s. We are a market segment worthy of equal billing with tour versions. You could have phrased it better.
UGOTAL
2 years agoDon’t bust your hernia belt, It’s just an expression…lol
Tony Covey
2 years agoFirst – Mizuno’s words not mine. Secondly, it wasn’t a knock on older players. The point was that the previous ST-200X was built exclusively to J-Spec. With the new model, the X can be built to standard or J Spec, effectively increasing its reach.
tscdave
2 years agoWho doesn’t want to try Mizuno equipment? Good article on what their new drivers are all about!
John T. Smith III
2 years agoPlease sign me up for the newsletter, because I am in the market for a new driver shaft for distance and performance. Thanks!
GilB
2 years agoThey LOOK amazing however performance is the key. Until they they are distance, sound, and dispersion competitive with the big boys of the driver clubs they’ll always be a second tier product. I’d love to try them as their appearance is awesome.
Mike
2 years agoNice looking drivers at a nice price. When I look at these, Cobra and other brands all under $450, you have to wonder why the big three need to charge $100 more. I had a bad experience with Mizuno irons some years ago & the annoyance is still somewhat fresh, so I probably wouldn’t purchase that brand. But in a few years when I’m in the market for a new driver, assuming my feelings will have subsided, I consider these