Gear: Srixon ZX4 Mk II, ZX5 MK II irons
Price: $1,199.99 with Nippon N.S. Pro Modus3 Tour or KBS Tour Lite steel shafts and Golf Pride Tour Velvet grips. $1,299.99 with UST Mamiya Recoil Dart graphite shafts
Specs: 1025 carbon steel body with SUP10 stainless steel face and progressive grooves. Hollow-body construction for the ZX4 Mk II.
Available: Jan. 20
Who They’re For: Golfers who want more forgiveness and distance with the feel of a forged iron.
The Skinny: The hollow ZX4 Mk II was designed to maximize ball speed and height for golfers who don’t want a set of miniature hybrids, while the ZX5 Mk II is a game-improvement iron created to deliver more yards with an enhanced feel.
The Deep Dive: Mid- and higher-handicap golfers come in all shapes and sizes, from athletic players who are new to the game to weekend enthusiasts who lack speed and don’t have time to practice. Lumping them all together and trying to design one set of irons that can deliver the performance everyone needs is almost impossible, so Srixon has two sets of game-improvement irons – the new ZX4 Mk II and ZX5 MK II – that share some technologies but are constructed differently and meant for different types of players.
The ZX4 Mk II and ZX5 MK II were designed with an updated Srixon technology called Mainframe that involves a series of grooved channels and cavities on the inner-facing side of the SUP10 stainless steel faces. The central portion of the hitting area is very thin, and in the ZX5 MK II, there are thin areas below the topline, in the toe area and above the leading edge. In the ZX4 Mk II, channels are below the topline and in the toe, and a secondary thin spot is in the center.
By strategically supporting the face but allowing large areas to flex at impact, Mainframe helps golfers generate more ball speed and distance across a more significant portion of the hitting zone. In the ZX4 Mk II and ZX5 MK II, the creation of channels also produced discretionary weight that was shifted to the sole toe area. That weight shift should increase stability.
Turf interaction is something elite golfers pay close attention to, but golfers who shoot in the 80s and 90s rarely think about it. Ideally, the bottom of an iron should work into and out of the ground efficiently so players can maintain speed through the hitting area.
The ZX4 Mk II and ZX5 MK II were designed with Srixon’s Tour V.T. Sole. Looking at the bottom of the irons, golfers will see they are divided in two from heel to toe. The portion behind the leading edge has a higher bounce angle, elevating the leading edge and helping the head skim through the ground without digging. The back of the sole has less bounce but does have trailing-edge relief, so if a golfer wants to open or close the face slightly to fade or draw a shot, effective turf interaction is maintained.
Most golfers only think about grooves when they talk about wedges, but Srixon designed different grooves in the ZX4 Mk II and ZX5 MK II irons based on what the clubs are designed to achieve. The 3-iron through 7-iron have wide grooves for versatility, while the 8-iron through attack wedge have narrower and deeper grooves to enhance spin and control on approach shots.
Straddling the line between a better-player’s distance iron and a game-improvement iron, the ZX5 MK II has a shorter blade length than the ZX4 Mk II, with marginal offset and a moderately wide sole. It won’t be visually offputting to accomplished golfers who want more distance and should appeal to mid-handicap golfers who want irons that look like they would be used by someone who shoots in the 70s.
The ZX5 Mk II should allow golfers to work the ball from side to side, but with its classic cavity-back construction and perimeter weighting the ZX5 Mk II will have more forgiveness than Srixon’s new ZX7 Mk II.
The ZX5 Mk II is available as a 3-iron through attack wedge with modern lofts. The 5-iron has 24 degrees of loft, and the pitching wedge has 44 degrees of loft.
The most significant difference between the ZX5 Mk II and ZX4 Mk II is the ZX4 Mk II is hollow, which allows the face to flex even more easily at impact for greater ball speed. The center of gravity is also positioned lower, so it produces a higher launch and more spin.
The ZX4 Mk II has a broader sole, longer blade length and more offset than the ZX5 Mk II. Those design attributes help make it more stable and forgiving than the ZX4 Mk II.
Available in 4-iron through attack wedge, it also has stronger lofts, with the 5-iron being 23 degrees and the pitching wedge having 43 degrees of loft.