Pros: FLT shafts use a flighted design, which helps golfers launch their long irons higher and with more spin. The FLT short-iron shafts provide a more penetrating trajectory for more control.
Cons: FLT shaft flexes correspond with weight, so golfers may not be able to match their desired shaft weight with their desired flex.
Who They’re For: Golfers who need more spin or more launch from their long irons to optimize their trajectory. Everyone from beginners to PGA Tour players can use the shafts effectively, but they’ll be most popular with golfers with moderate-to-slow swing speeds, or any golfer who generates low-spin launch conditions.
Selecting the proper iron shafts is one of the most important equipment decisions golfers make. It’s an issue of quantity. Most golfers carry about 7-8 irons in their bag, so if they choose the wrong iron shaft, they’ve made the game harder than it needs to be with half or more of their clubs.
The good news is that there’s a wider selection of quality iron shafts than there has ever been, with recent growth in models that are designed to help golfers hit their iron shots higher and farther, while still maintaining PGA Tour-quality consistency and feel.
KBS is one of the leading steel shaft manufacturers, and already offered a wide variety of models prior to its newest shaft launch. Company representatives felt KBS was lacking a product for a particular segment of golfers, however, so it developed its new FLT shafts.
FLT shafts ($31.95 each) have a flighted design, which helps certain golfers optimize the performance of each iron their bag. The long irons shafts have progressively softer tip sections, which helps golfers increase their launch angle and spin rates with those clubs. For the right golfer, the design will help them hit their iron shots farther, and stop shots on the green more quickly. In the short irons, where height and spin are easier for golfers to generate, the FLT shafts are stiffer, which creates the flatter trajectory most golfers prefer with their scoring clubs. The crossover point between the higher-launching long irons and lower-launching short irons is the 7 iron.
Like all KBS shafts, FLT models have a constant weight, which means that long iron shafts and short iron shafts will be roughly the same weight through the set. Shaft weight is dependent on flex, however, as softer-flex models are lighter than stiffer-flex models. So if you’re looking for a really heavy, regular-flex shaft or a really light, extra-stiff-flex shaft, these aren’t for you.
Keep in mind that KBS shafts do not have reinforced tip sections like many other iron shafts, which gives them a slightly higher balance point and can decrease swing weight by 1-2 points. I personally like the feel of KBS shafts and their slightly higher balance point, but some golfers won’t.
For this review, I tested the new FLT shafts head to head against KBS Tour shafts of the same flex and weight (130X) in 4 irons, 6 irons and pitching wedges. Each of the shafts were installed in Callaway’s Apex Pro ’16 irons, and were built to my specifications (standard grips, standard length, 1-degree strong lofts, 1-degree flat lie angles).
I performed my testing at the Launch Pad at Carl’s Golfland in Bloomfield Hills, Mich., where I hit the 4 irons, 6 irons and pitching wedges on Trackman IV with premium golf balls. I hit 3-6 solid shots with each iron, and then removed the outliers from the final data in an attempt to compare only the most similar strikes. Results were normalized.
As you can see from the data, there was a significant difference in the flight of the 4 irons with the two different shafts, but less of a difference with the 6 irons and pitching wedges.
As expected, the FLT shafts caused 4 iron shots to launch higher (0.8 degrees) and with more spin (729 rpm) than the KBS Tour shafts. I’m not a low-spin player, which is one of the target audiences for this shaft, so the added launch and spin of the FLT shafts caused my 4 iron shots to fly shorter. Golfers who launch their irons too low or with too little spin, however, will likely see a distance increase when using the FLT shafts.
As I moved closer to the short end of the set, the two shafts started to perform more similarly. Theoretically, the 6 iron shots with the FLT shafts should have launched slightly higher and spun more than 6 iron shots with the KBS Tour shafts, but I actually saw a slightly lower launch angle (0.5 degrees) with the FLT. The spin was higher, though, by 211 rpm. With the pitching wedges, the results were again quite similar. The FLT launched 0.9 degrees higher, but actually spun 271 rpm less than the KBS Tour shafts.
Stepping back from the numbers, I was impressed with how similar the feel was between the KBS Tour and FLT shafts. Yes, I could feel that the FLT shafts were more active in the tip with the 4 irons, but they felt nearly the same in the 6 irons. By the time I got to the pitching wedges, the two shafts were indistinguishable. The KBS Tour is considered one of the better-feeling iron shafts currently available, so KBS’ ability to replicate that feel in the FLT will be a plus for the majority of interested golfers.
Looking more broadly, trends in shaft design tends to go hand-in-hand with trends in club head design, and the FLT shafts are no exception. Equipment manufacturers continue to strengthen the lofts of their distance irons; they have to in order balance the launch equation, as their faster ball speeds create a higher launch angle and more spin.
While the improvements to iron design have allowed golfers to hit their mid and short irons farther, many golfers continue to struggle to hit their long irons high enough or consistently enough for them to be effective. And based on my testing results, it’s clear that the FLT shafts can make long irons more playable for certain golfers, and maybe even keep long irons in a golfer’s bag that might otherwise be kicked out for higher-flying hybrids or fairway woods.
As always, I recommend that golfers get properly fit for iron shafts, which means visiting a reputable club fitter in your area. So if you’re in the market for new irons or iron shafts, you can get started by going through KBS’ Online Fit System, which upon completion lists KBS-certified dealers in your area.