The new Callaway Rogue iron family, which includes three varieties, makes the case that as challenging and technologically remarkable as it might be to make an iron with a spring-like effect equal to that of a driver – and they’ve done exactly that – it is as equally a demanding exercise to find a way to make these ultra-modern irons sound more like the good old days.
The Rogue iron line, made up of the standard game-improvement style (Rogue), a more compact players distance iron (Rogue Pro) and a strong-lofted, lighter weight, distance-focused option (Rogue X), is nothing short of Callaway’s most ballspeed-driven iron collection ever. A newly conceived cupface, which has been continually reiterated since it first appeared in the Big Bertha irons in 2014, features a variable thickness face, as well. That means selective areas of the face are thinned to allow more flexibility at impact, while the thin lip that wraps the face around the topline, sole and toe perimeter also more easily flexes.
“Our 360-degree cupface may appear to be an idea that keeps getting rehashed, and may appear in people’s minds to be old, but the lessons we’re learning are new,” said Scott Manwaring, Callaway’s director of design for irons. “We’re now at the point where our [Variable Face Thickness (VFT) designs] aren’t simply optimising for ballspeed, nor are they simply optimizing for launch angle, now we’re starting to find ways to adjust for spin. So for certain models we can change our VFT for spin but not affect speed.”
The upshot is the new Rogue irons launch shots more efficiently and specifically for the requirements of the particular iron within the set.
The Rogue family of irons go beyond the thin cupface design and incorporate two key features that go a long way to enhancing both launch and feel. On the launch side, Callaway’s engineers took the learnings from the high-end Epic concept irons to further develop metal injection moulding (MIM) processes for fashioning the internal tungsten weighting that more specifically locates the centre of gravity (CG) at the proper height within the head. The tungsten infused part rises up from the sole in what Callaway calls its “internal standing wave”.
But you can get the CG correct and you can marry it with a very thin face design, and still you might find yourself with one large problem: an iron that sounds clanky or tinny or anything other than classic. While other manufacturers have been using fillers of one kind another behind the face or in the cavity, in some cases to even support a thinner face design and thus contribute to its ability to flex, Callaway’s team believes the speed in the iron is coming from the metal and the way it’s designed in the iron. What the filler does is control unwanted vibration, while still allowing the face to flex at a rate equal to the co-efficient of restitution (COR) limit implemented by the R&A and USGA.
That kind of function couldn’t be accomplished with standard golf club materials, says Alan Hocknell, Callaway’s senior vice president of research and development. The urethane compound, which sits in the lower half of the iron in line with where impacts occur, is impregnated with millions of tiny pockets of microscopic spheres of air. The technology has been used in the auto industry to reduce weight and provide “improved dimensional stability”.
“It allows that material to behave in a very unusual way by having it collapse for the split fraction of a second that the face is deflecting,” Hocknell said. “So it doesn’t resist the motion of the face, but it’s there in a damping tuning mode to reduce the amplitude and the duration of the vibration.”
In essence, it solves the sound challenge while allowing the optimum degree of face deflection. As the face deflects, the ball goes faster, higher and farther. Meanwhile, the use of the urethane microspheres allows the fast-faced multi-piece iron to feel more like a traditional, solid one-piece design.
“I do not believe you need urethane to help you get to .830 COR,” Manwaring said. “I believe that the true benefit of urethane is changing the COR sound curve.”
The Rogue iron lineup’s three alternatives are aimed at certain player types. The standard Rogue uses a blade length similar to that of the Steelhead XR, but with a larger area of the face that produces near peak ball speed.
The Rogue Pro iron includes the same distance features as the standard Rogue, as well as the microsphere-impregnated urethane filling, but wraps it in a more better player-friendly compact shape.
Finally, the Rogue X iron takes some learning from Callaway’s niche GBB Epic Star iron introduction last year, which was aimed at golfers seeking speed and distance through lighter weight and stronger lofts.
The oversized Rogue X uses longer lengths in the longer irons, lighter weights and stronger lofts through the set, including a 41-degree pitching wedge.
“The thing that most people would ask is, ‘Aren’t you just jacking lofts,’ and the answer is, ‘No, we’re not,’” Hocknell said. “The concern is can you still launch a club that’s got less loft the same way? Well, because of the construction of the head and the configuration of the set we’re able to get those irons to launch broadly equivalently to the standard set.”
Hocknell says the key to getting that kind of launch is the Rogue X’s wider sole and general oversized shape. “That allows us to take loft away without losing launch angle,” he said, noting that he doesn’t think the Rogue X is in any way only limited to high handicappers.
Rogue irons will be in stores across Australia from February 9, for $159.99 each (steel shafts) or $174.99 each (graphite).
All three irons will be joined by a matching lineup of Rogue and Rogue X hybrids. Like the Rogue fairway woods, the hybrids are the first to feature Callaway’s “Jailbreak” technology where internal vertical bars just behind the face join the crown and sole to stiffen the body and concentrate more flexing in what ultimately becomes a thinner face in both on-centre and off-centre hit locations.
Both the Rogue and Rogue X hybrid also utilise the high-strength Carpenter 455 steel face cup design from the fairway woods, where the face wraps around the crown and sole.
The standard Rogue will be offered in five lofts (17, 19, 21, 24 and 27 degrees), while the larger and more forgiving Rogue X will include six lofts that stretch to a strong 8-iron (18, 20, 23, 26, 29 and 32 degrees).
Rogue hybrids will be in stores across Australia from February 9, for $359.99 each.
