Key Takeaways:

  • Wide sole, hollow-body game-improvement irons with a forged-like feel
  • Lowest center of gravity in Srixon line for easy launch and high flight
  • Progressive Grooves and signature Srixon V.T. Sole for turf interaction
  • $1,299.99 per set in steel, $1,399.99 in graphite.
  • Available at retail March 5

The new Srixon ZX4 irons surprised us a little. There are two layers to that statement.

We knew the ZX5 and ZX7 irons were in the pipeline as an on-schedule update to the two-year-old Z-85 irons. But the ZX4s? Totally under the radar until the samples showed up.

That’s the first-layer surprise. The second-layer surprise?

Srixon has something here you’re definitely going to want to try.

Srixon ZX4 Irons – Hollow to the Core

Hollow-body irons certainly aren’t new. Heck, even forged darling Mizuno has the HMB-20. But the Srixon ZX4 irons are, depending on how you look at it, either category busters or misfit toys. The sole width screams “super game improvement” but the topline and offset suggest “player’s distance.” The ZX4’s loft structure will surely get Torch and Pitchfork Nation riled and angry but it’s not out of line for game improvement irons. But, then again, the relatively short blade length and forged-like sound and feel make you think player’s distance again.

OK, Srixon, what gives?

“We’re creating more overlap into the game improvement category,” says Dustin Brekke, Srixon’s Director of Engineering. “A few years back, we had the 355 series but I don’t think we fully got behind it.”

When Cleveland returned as a full-line OEM, it positioned itself firmly in the GI/SGI categories. Srixon bridged the gap from better player-ish GI irons (like the Z585, the 2018 Most Wanted GI iron) to cavity backs and blades. The ZX4 puts Srixon squarely in the game improvement category. Sort of.

“The biggest thing you’ll see between this and Cleveland is the size of these irons,” says Brekke. “It’s a better player-focused shorter blade length. It’s a smaller look in the ZX4 that you’re just not going to see in Cleveland irons.”

So, into what category does the ZX4 fall? Let’s just say it’s a “super-forgiving hollow-bodied game improvement player’s distance iron with forged feel.”

There. That should clear things up.

Hollow Mainframe

The Srixon ZX4 shares considerable DNA with the ZX5 irons: two-piece construction featuring Srixon’s Mainframe face design. We discussed Mainframe at length in our story on the ZX5/ZX7 launch in November. The Cliff Notes version, however, says Mainframe is a variable-thickness face designed using Srixon’s latest Artificial Intelligence software. A unique pattern of channels, cavities and grooves is milled into the back of the face. The end result is—all together now—optimized ball speed over a larger area of the face.

The face material itself is HT1770 steel (the HT is for High Tensile) while the head is 431 stainless steel. While neither qualifies as “forged” in the traditional sense, the combination results in a forged feel that will make you a little weak-kneed and squishy.

As mentioned earlier, the ZX4’s sole width is very much SGI. Srixon does a nice job of hiding it at address but there’s no denying the ZX4 is broad in the beam.

“It’s deliberate, especially in the long irons,” says Brekke. “The hollow body combined with the wide sole and a short hosel, plus tungsten weighting in the mid- and long-irons, gives us one of the lowest centers of gravity on the market.”

If you’re thinking the ZX4 sounds an awful lot like Srixon’s utility irons, you’re on the right track but you’ll need to go back a generation to the U-85s.

“Those utilities had a much wider sole compared to the new generation ZX utility irons,” says Brekke. “A lot of the U-85 performance and technology is there throughout the ZX4 set along with Mainframe and a few new nuggets along the way.”

Specifically, we’re talking about Srixon’s signature V.T. Sole and its new Progressive Grooves.


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Groovin’ with Sole

As the Srixon ZX4 set progresses into the short irons, the heads obviously get less hollow. The blades also get a little shorter and heavier. And once you hit the 40-degree mark in loft, much of Mainframe’s hot-face benefit starts to drop off. The impact is more glancing than it is blunt force.

“As we progress through the set, we’re focusing on consistency and what players look for in launch angles and spin,” says Brekke. “That’s where we see the Progressive Grooves in the set.”

As we learned with the ZX5 and ZX7, Progressive Grooves are all about consistency. The ZX4 long- and mid-irons feature wider and shallower grooves. The grooves get more aggressive in the 8-iron through pitching wedge. The scoring irons have deeper grooves that are closer together to provide consistent spin on your approach shots.

Srixon irons are known for their turf interaction, thanks to the V.T. Sole. The V-shape on the sole helps the clubhead glide through the turf, even if you hit it a tad fat. The V.T. Sole is featured in the ZX4, which may seem like overkill considering it already has a wide sole.

“Our target player is more of a sweeper-type player,” says Brekke. “They don’t have as steep of an attack so they struggle with chunking behind the ball. The wider V.T. Sole with the low CG helps.”

Loft Alert

So, yeah, the Srixon ZX4 irons have strong lofts. Not crazy strong, mind you, but they are what they are.

“It’s tricky,” says Brekke. “We’re trying to design sweet spot and CG location and overall performance to optimize distance and carry at every loft. But there’s this unfortunate reality of the need to perform well and win in fitting environments.”

OEMs know they don’t want to be the short knocker in the fitting bay. That’s why the ZX4’s 28.5-degree club is a 7-iron and not a 6-iron. The standard ZX4 set is 4-iron (21 degrees) through gap wedge (49-degrees). If Srixon labeled the set 3-iron through pitching wedge instead of 4-iron through gap wedge, would Torch and Pitchfork Nation be as cranky?

“It’s semantics and, in many ways, it’s a silly game,” says Brekke. “But on the performance side, if we did mark the 33-degree 8-iron a 7-iron and somebody compared it to their own 33-degree 7-iron, they will hit this one higher and it will get off the ground easier. But put the same swing on both irons and compare your best shots and you’ll  see very similar spin, control and distance.”

Translation: If you need to hit a 150-yard shot and you know which club goes that distance, what the hell difference does it make what number is on the bottom?

“The driver is the only club in the bag you’re trying to hit as far as you can,” adds Brekke. “So the conversation really becomes, ‘What iron do you need to go a certain distance? What’s going to give you the most consistency and control?’ That’s going to show itself in spin, launch and turf interaction. The number on the iron doesn’t matter. It’s just a number.”

Srixon ZX4 Specs, Price, Availability and Final Thoughts

I’m not sure we’re any closer to figuring in what category the Srixon ZX4 irons belong. GI? SGI? Player’s distance?

All of the above?

Maybe it’s best to call them nice-looking irons with a reasonable offset, topline and blade length. And even though they’re not forged, Srixon has managed to instill a forged-like feel you don’t usually get in hollow-body irons. A couple of mid-winter range sessions show the ZX4s are silly easy to launch, fly high and, thank you lofts, go like hell.

Even with the widest sole in the ZX family, the Srixon ZX4 doesn’t really look out of place with its slightly older brothers. The ZX4 blade length is barely a millimeter longer than the ZX5 and just two to 2 1/2 millimeters longer than the ZX7. The topline is only one millimeter thicker and the offsets are only a millimeter or so deeper.

Srixon put some thought into its choice of the Nippon N.S. Pro 950GH neo as its stock steel shaft. Nippon describes the 950GH neo as mid-launch and it’s specifically engineered for stronger lofted irons. The 950GH neo has what Nippon calls a “flowing” kick-point to create a kind of reverse-whip at the tip to optimize spin.

The 950GH neo is a lightweight shaft. The R-flex comes in at 94.5 grams and the S-flex at 98 grams. Srixon does offer any steel shaft in its catalog at no upcharge.

The stock graphite shaft is the UST Mamiya Recoil 760 or 780 and the stock grip is the Golf Pride Tour Velvet 360.

The basic set (4-AW) is available for righties. Pricing is $1,299.99 in steel and $1,399.99 in graphite. Since the gap wedge is available for righties only, the standard left-handed set will be 4-PW and will retail for $1,137.99 in steel and $1,224.99 in graphite.

The Srixon ZX4 irons will hit retail on March 5. Pre-order is available on February 22.

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