Iron shafts are the forgotten younger sibling of the golf shaft family. Where’s the love?
Most of the avid golfers we see in our shop will spend hours combing WRX forums, reading various reviews, asking questions and trying out countless different options for their new driver shaft. For some reason, these same golfers simply don’t pay attention to the shafts that go into their irons, even though there are typically at least eight of them in their bag versus just one driver. Too many golfers use the same iron shafts they’ve been gaming since the last time they were fit (usually at a demo day, a couple of sets ago) or use whatever might come as stock.
Although you surely don’t fall into this category, you might have a friend or two that does. So to help, we did data-driven, head-to-head comparison of several of the top iron shafts for better players. Our findings indicate that everyone should take a fresh look at what shafts should go into their next set of irons. Putting the wrong shaft in one club can show up on the scorecard. Now imagine having 7 to 10 shafts that don’t match your swing. It’s not a pretty picture.
As we began the test, I didn’t think any single shaft or shafts would surpass the others in total performance. Instead, my hypothesis was that certain shafts would distinguish themselves in one or two areas and potentially fall behind in others. For example, the longest shaft would likely be the least consistent.
For each shaft in our test, I asked four low-handicap golfers (-2 to a +2) to take five shots with a 4 iron and PW with a stiff-flex shaft using Mizuno JPX-825 Pro iron heads for each shot. We threw out obvious mishits, but included slight misses as they’re part of the game. A shaft’s performance must be measured by how misses are managed. The number of excluded shots was low and very consistent across the shafts, however, indicating that these were caused primarily by a swing issue and not a result of the shaft.
We used a Foresight GC2 launch monitor to track all the results. The order we hit the shafts was random and the shots were broken into three different hitting sessions to ensure that fatigue didn’t skew any numbers.
Here are the shafts we used in our testing:
- Aerotech SteelFiber 125S
- KBS C-Taper 120S
- KBS Tour 120S
- KBS Tour-V 110S
- Nippon N.S. Pro Modus 120S
- True Temper Project X 6.0
- True Temper Dynamic Gold S300
- UST Mamiya Recoil 125S
We tracked the average ball speed, launch angle, backspin, carry distance, carry deviation, decent angle and distance offline.
Shafts perform differently for different golfers. All the shafts performed well, however, and if you spend any time looking through the data you’ll see that the single biggest finding is that my original hypothesis was wrong. On average, there are very limited performance differences between shafts when data from the four golfers is averaged. Yes, there are some minor variances, but given the sample sizes we cannot conclude anything definitive.
The real variations come when we look at how each shaft performs for individual golfers*. Take the Aerotech SteelFiber performance for Golfers A & B from the table below.
For Golfer A, the SteelFiber was his longest 4 iron and flew nearly 7 yards more than his average carry distance. It was the shortest shaft for Golfer B, however, and 6 yards below his average. The only way to ensure you’re playing with the best shafts is to go through a thorough fitting where you’re able to hit several options, ideally with the same head.
How a shaft feels should not be the first criteria used when selecting a shaft. Other than in extreme cases, it’s best not to assume how a shaft is performing, but instead rely on a launch monitor to provide unbiased data. You might be surprised how your perception of feel might be changed by performance. For example, our testers expressed concern about the dispersion with the Nippon N.S. Pro Modus 120S and UST Recoil 125S shafts. The numbers show that the dispersion for both shafts were right in the middle of the pack. Feel is best used as a final decision when two shafts are performing very similarly. Here is the summary feedback on feel:
- Project X 6.0: An incredibly stiff, solid feel. Not much in terms of the shaft loading/unloading and what the ball is doing at impact.
- KBS Tour: Lots of feel throughout the swing as the shaft flexes. It feels like it “pops” at impact. Also, it feels more flexible than it actually is.
- Nippon N.S. Pro Modus 120: Incredibly smooth-feeling throughout the swing, a definite favorite. Only concern is if the shaft too soft and distance and offline consistency are sacrificed.
- UST Recoil 125: Feels very good with a lot of pop, like a KBS Tour on steroids. Despite being graphite, it feels very stable and many would play them. Testers knew when and where misses were, but the feedback wasn’t harsh.
- KBS C-Taper: Heavy and stable, a cross between the Project X and KBS Tour. The weight and stability feel good, but the ball doesn’t jump off the face.
- Aerotech Steelfiber: The Recoils feels nice off the face, but the SteelFiber feels more stable and smooth throughout the swing. It really feels like steel.
- True Temper Dynamic Gold S300: Feels like home, very familiar.
- KBS Tour-V: Very smooth, but light and flexible. It would take a while to get used to the lighter weight.
Both the Recoils and SteelFibers limit harsh, negative vibrations on mishits, but still feel solid throughout the swing and at impact. The shafts provided enough feedback that the players could control ball flight and knew where exactly they hit it on the face. Graphite performs, even for very good golfers. Living in Hilton Head, I got a front row seat for Matt Kuchar’s win with a set of SteelFibers.
Despite being doubters before the testing, all of our testers indicated they would strongly consider both high-end graphite options for their next set of irons. The feel feedback indicated the Recoils could be felt loading and unloading during the swing more than the SteelFibers and provided a “pop” at impact. The SteelFibers felt stable like steel throughout.
Note*: In this study, we attempted to correlate shaft performance differences with differences in the golfers’ swings. We were unable to do the correlation as a result of our limited sample size.
The original purpose of this testing was to provide a data-driven guide to help better players select what shafts to put in irons. As with much in golf, my research findings didn’t turn out quite that simple.
What this testing really proves to me, and hopefully for you, is that everyone can really benefit from taking a fresh look at what they’re playing and do a thorough fitting. What you are playing may not be the optimal shaft for you.