Bryson DeChambeau made headlines for winning the U.S. Open. Part of the story was his latest foray into what, by mainstream standards, qualifies as unusual, perhaps even oddball, equipment choices.
The one-sentence summary? Bryson is playing 3D-printed irons with faces that have bulge baked in.
That last part of the design is uniquely Bryson but it may be enough to make you wonder if you need bulge on your irons.
What are Bulge and Roll?
Before we get to that, let’s take a step back and explain what bulge and roll are and what they do.
Integral to metalwood design, bulge and roll are present on every driver, fairway wood and hybrid face. There’s an element of semantics at play here because both are just more specific ways of saying curvature.
Bulge is the curvature of the face from heel to toe. Roll is the curvature from top to bottom. As we understand it, Bryson’s irons have bulge, but not roll.
Over the years, companies have developed unique and proprietary bulge and roll radii but, regardless of the design twist any given manufacturer puts on the idea, we’re still just talking about variations of curvature that serve to mitigate the gear affect on off-center contact.
And that brings us to our next question.
WTF is the Gear Effect?
To understand the gear effect, you can think of the ball and the club as a pair of interlocking gears that turn towards each other when impact is made anywhere but on the center of gravity projection (for simplicity, you can think of that as the sweet spot).
Even if the related terms are new to you, you’ve definitely experienced the gear effect on the golf course. Explained simply, the gear effect is the reason why high face shots spin less, low face shots spin more, toe shots add what’s often called draw spin, and heel shots create slice spin.
Using right-handed golfers as our example, bulge works by pushing the starting line of a toe miss to the right and heel shots to the left.
When you don’t hit the center of the face, bulge corrects, or at least alters, where your golf ball starts.
Without the starting-line adjustment that bulge provides, heel shots would slice even further right while toe shots would hook harder left.
It’s important to understand that bulge and roll radii can vary from model to model. They’re part of the design package that seeks to optimize performance for the target golfer. With that, bulge is not a cure-all, which is part of the reason why some of our toe misses still fly too far right and others hook too far left.
Bulge on Iron Faces
In modern club design, bulge and roll have been exclusive to metalwood face design. The conventional wisdom – arguably, the physics – is that for bulge to have any benefit two things are required: length and center of gravity depth.
In this case, “length” is just a synonym for speed while “CG depth” refers to how far back in a clubhead the true center of gravity is.
With metalwoods, you have both speed and depth. We swing them faster and the bigger heads give the CG plenty of room to live deep behind the face.
But, for most golfers and most designs, the same can’t be said for irons. Compared to metalwoods, we swing them considerably slower and the compact nature of irons means the centers of gravity never sit far from the face.
In theory, bulge serves no real purpose on irons because they lack both the length (speed) and CG depth. More than one R&D guy has told me there is no appreciable gear effect on irons.
So What About Bryson?
And that brings us to Bryson’s Avoda irons.
Unlike conventional designs, Bryson’s irons have bulge baked into the face design. Bryson described them to Golf Channel’s Johns Wagner like this: “The curvature of the face is kind of like a driver or a hybrid or whatnot. It kind of caves in on the heel and caves in on the toe.”
That’s bulge, and it shouldn’t serve any purpose on an iron, but …
Bryson isn’t the typical golfer. His ball speed with an 8-iron is faster than average golfers generate with their drivers. His ball speed with a 5-iron is 164 mph. For context, the PGA Tour average with a driver is 171 – just six mph faster.
Bryson has the speed. The CG depth … that’s a different story.
The center of gravity depth on Bryson’s irons is constrained by the limits of the geometry itself. It can’t go deep because there is no deep.
That said, there is a school of thought that says that as speed increases, CG depth becomes less important. I should also point out that both MOI and blade length are factors in this equation.
The bottom line is that Bryson believes his bulging irons better correct toe misses and, while the R&D guys I spoke with are dubious of the claim, none has tested irons with bulge – and certainly not at Bryson’s speed.
With that, it’s not surprising that Bryson would be the first to use an iron with bulge. He’s been labeled a mad scientist, though I prefer to think of him as the Chrisopher Columbus of golf gear.
While he’s clearly looking to better his game, finding something that nobody has found before is part of the allure, perhaps even the fun, in how he approaches his equipment.
He has an explorer’s spirit which can be a bit of a double-edged sword. Sometimes what you find has already been found, sometimes it isn’t what you think it is, but if you search long enough, you might just find what you’re looking for.
Perhaps Bryson has found his personal Holy Grail.
Do I need Bulge in My Irons?
So, you may be wondering, with Bryson playing irons with bulge, should you be doing the same?
The shorter answer is almost certainly no. I’d be willing to bet you don’t have the speed for it to matter.
And even if you did, it’s unlikely that any large manufacturer will bring irons with bulge to the market.
First, as I said, most of us don’t have the speed for it to matter.
Second, while it might make for a good marketing opportunity, they’d almost certainly be more expensive to produce, likely to the point of being non-viable in the mass market (at least in the short term).
Finally, golfers are a picky bunch. We like things to look a certain way. There’s a reason why square and triangular drivers faded quickly despite their MOI benefits. Likewise, despite their ability to help the most common miss in golf, you’ll find exceedingly few offset drivers on the market.
Looks matter to most golfers.
Bryson is different. He’s definitely not like most golfers. History has shown us he embraces the unconventional and will try (and play) just about anything if he believes it will help his game – regardless of what it looks like.
That’s the lesson we should all take from his irons.
vito
2 years ago
“There’s a reason why square and triangular drivers faded quickly despite their MOI benefits.” Yeah, did you try them? They were some of the shortest drivers out there. And they didn’t correct enough dispersion to offset the loss in distance, at least for me.