Last year in August, I introduced the now-famous AutoFlex golf shaft to the English-speaking world here on GolfWRX (Korea’s Autoflex shaft: Challenging the conventional wisdom of golf).

Created by Dumina Co. in South Korea, the upstart shaft challenged the commonly-held view that flexible shafts are not only straighter but longer as well. In the weeks that followed, the neon pink shaft exploded onto the golf scene fueled by a series of videos from TXG’s Ian Fraser and Matt Blois, who seemed equally amazed at the unexpected results. And from the depths of obscurity where so many would-be ‘game changers’ remained, the legend of the Autoflex was born.

Looking back, it may have been the perfect storm – an innovative, ultralight, and flexible shaft with a mysterious “Korea Hidden Technology” appearing at the height of the golf boom brought on by a pandemic. The fact that the manufacturer refused to patent their know-how to protect the technology only added to the intrigue.

Shortly after TXG first introduced the “mysterious Autoflex,” the pink shaft made its appearance on all the major tours. Some of the tour pros to put Autoflex in play included Adam Scott, Louis Oosthuizen, Branden Grace, Ernie Els, Fred Couples, and Michelle Wie West, with dozens more requesting to try the new shaft.

Although the specific technology behind the shaft remains hidden, tens of thousands have since taken the plunge to track down the bright pink shaft despite the high price tag.

According to Dumina, Autoflex shafts are now available in most golfing countries and major OEMs such as Titleist and Srixon/Cleveland/XXIO have added the Autoflex to their premium fitting matrix.

So what have we learned in the space of one year? Recently, I spent several days scouring the Internet to see what the people have been saying about the shaft in posts, reviews, videos, forums, and testimonials.

From the thousands of actual golfers, club fitters, and pros who have tested or played the AutoFlex, the consensus is:

• The majority of users seem to agree that the Autoflex driver shaft is the real deal in providing increased ball speed (as high as +8mph) with overall carry distance and accuracy, just by changing a shaft and without any additional effort (i.e. speed swing or physical training).
• The shaft seems to work best when the overall swing weight of the driver is between C8 to D0. This is radically different from the ‘normal’ D2~D5 swing weight for heavier, stiffer conventional shafts.
• Many raised the concern that swinging such a flexible shaft would not readily translate to swinging a stiffer shaft on the following shots. However, many users, including myself, reported that the swings felt no different going from Autoflex to a conventional shaft and back again during the round.
• Despite the shaft feeling extremely whippy when waggled, golfers said they came to trust the clubhead to catch up to the ball at impact even when swung hard. A few golfers with an aggressive transition said the shaft actually helped to smooth out their tempo on all their clubs.
• Initially thought to target the slow swing speed golfers with a smooth transition, the shaft has been proven by numerous users to perform well for faster swings in excess of 120mph with aggressive transitions.

The above summary may seem to paint the Autoflex as the new golf messiah, but not all reviews were glowing.

I would be remiss not to mention the handful of golfers who saw no increased benefit whatsoever with the Autoflex. There were also a few golfers who likened the shaft to “snake oil”, but most of them did not seem to have actually tried one for themselves.

Most famous perhaps is the video review by Rick Shiels, who was disappointed at the lower-than-expected results. However, many replies on the channel pointed out that the swing weight may have been too heavy (D4~D5), and needs to be fitted to the recommended balance as it is not a “plug and play” shaft.

There were also some instances where golfers reported their shaft breaking or cracks appearing along the shaft. Luckily, the shafts are equipped with a warranty sticker and many reported that the company was quick in response with a replacement. On their website, Dumina recommends utmost care during club fitting as the walls of the butt end and tip are quite thin (be careful when tightening that vice!).

On the whole, however, the online feedback seemed overwhelmingly positive, and that the Autoflex shaft can indeed improve driving performance when dialed into their specified swing speeds.

Co-founders of Dumina Co., Chairman Gun-yul Park and CEO Doona Jeong.

The inevitable questions soon followed. What’s their secret? Many guesses were thrown into the hat, ranging from non-Newtonian materials to KHT being an elaborate marketing scheme.

Could it be all along that golfers can benefit from using a much lower-flex shaft than their current gamers? I have tried several times to coax Dumina into giving me some hints, but so far, they gave nothing away other than stating that their tech and materials are capable of hundreds of new combinations.

According to its two-year product cycle, Dumina plans to release its new shaft models in the fall of 2022.

Other common questions I’ve seen were about their fairway and iron shafts. These shafts cost less than the driver shaft ($790) but are still expensive enough to give most golfers pause. The fairway wood and hybrid shafts retail for $675 each, while an iron shaft will set you back at $210 per shaft. Since becoming smitten with the driver shaft last summer, I managed to save up for the SF505 Autoflex shafts to be installed in all my woods and irons 6 months ago.

So are they worth the money? Below is my experience using the Autoflex SF505 shafts in all my woods and irons.

AutoFlex Driver and Woods

I have been using the SF405 shaft in my Cobra F9 since last year, and switched to SF505 with SIM2 Max 9° head early March. Despite the small fortune spent, I have been quite pleased with the results. When built to 45”, my driver came to C8 with the 24g stock weight in the head. It was good, but I wanted to feel the clubhead a bit more on the downswing. I
added about two grams of lead tape to bring the balance slightly past C9, and it is perfect for my average swing speed of 95mph. This setting is very comfortable to swing throughout the round, and my overall driving distance increased just under 20 yards.

As many users have attested online, one amazing benefit of the Autoflex shaft is that it allows me to feel the shaft loading as would a faster player swinging a much stiffer flex at 110+ mph. Thus, even at my slower swing speed I can feel the shaft actively loading and releasing explosively through the impact. The feeling is nothing short of glorious, and I believe this addictive feeling is a big part of the Autoflex charm. With the success of the driver shaft, I changed all the shafts in my woods and irons to the SF505 this March.

Driver: SIM2 Max 9° total 45” @C9; Fairway woods 3,5,7: Knuth High heat @D0; Irons: Yonex CB-301 5-P
@C9~D1

The distance gain with my 3-wood (210-220 yds) was barely noticeable, but the 5- and 7- wood carry distance increased by 10~12 yards. The fairway woods and hybrid are all from Knuth Golf, which came with Fujikura Atmos shafts at D2~D3. After switching to Autoflex, the lighter club heads coupled with the 46g pink shaft came to D0 swing weight. Just like the driver, the woods felt light and whippy compared to their conventional counterparts.

I find I don’t need to swing harder for the extra distance and the smoother tempo allows me to hit the center of the face more often. As a result, there is less chance of cold-topping the ball or pulling it left, and I am less afraid to pull out the longer clubs. The distinct kick at impact is also felt in the woods, but not as much as the driver. Depending on my condition and course, I switch out my 7-wood with the 4-hybrid. The hybrid feels a lot like a regular club, but a much lighter weight can be felt when compared to a normal hybrid club.

AutoFlex Irons

I tested both of the SF405 and SF505 iron shaft models and chose to go with the latter. I used Golf Pride Velvet Lite grips to get the swing weight between C9~D1 throughout the set.

Although the stiffer model of the two, the 505 shaft is still very light at 52g even when uncut. Unlike the driver shafts that range up to SF505XX flex for high-speed swings, the current iron shaft models are for average swing speed golfers between 80-100mph (driver SS).

Before switching, I played MFS Matrix Program 70 shafts weighing 79g uncut, and NS pro 950s steel shafts before that. My idea was to go lighter and still maintain adequate stiffness for control. I had pretty good success with the Matrix graphite shafts and carried on average 140~145 meters (153~158 yds) with my 7-iron on the course.

At first, the SF505 shaft actually didn’t feel too different. Perhaps I was already used to the lighter overall club weight from using the Matrix shafts. Also, the waggle test still produced a lot of whip, but not to the level of the driver and fairway shafts. Right away, I felt I could swing hard or smooth and still feel the clubhead following into the impact zone quite nicely.

It took about a week to get better acquainted with the new swing weight, but the overall transition into the new shaft was quite easy. I now average 150~155 meters (164~169 yds) with the same 7 iron (34 degrees loft). The spin is about the same as before at a low 4000rpm range, but the ball launches a tad higher for that extra carry distance. For those who play often in windy conditions, the added peak height may not be beneficial.

On the whole, the Autoflex iron shafts did improve my distance, swing tempo and accuracy over the last two shafts I’ve used. While I have seen equally good distance gains with other premium carbon shafts such as Steelfiber and MCI, there is no doubt that my dispersion got better. My iron play from within 150 yards improved noticeably, and I can swing more uniformly throughout the round.

Also, dropping down one club into the green helped both my GIR and putting average. I was a decent iron player to begin with, but the added distance with less exertion made the game easier on the body and the scorecard.

Looking at my past five-game average on a GolfZon simulator, I saw significant gains in all aspects of my game. To be sure, it is a simulated golf round and can’t compare to the actual course, but my numbers have all jumped up.

Compared to the tens of thousands of Korean golfers in my handicap/skills bracket, I am well above average except in putting. My driver averaged 226.8 meters (about 250 yards), launching at around 12~13° with 1900~2000rpm. This is an increase of about 20 yards B.A,

(Before Autoflex) and FIR has also jumped from the previous 55% to 74.2%. Greens in regulation improved by about 11% to 76.6%, and this is the indication that my iron play has gotten much more effective in terms of distance and dispersion. I have played over 370 virtual rounds on GolfZon over the past 12 years, and I can honestly say that my numbers
have never looked better. If I can only take these numbers onto a real course, I’d be golden.

Conclusion

If I had to list the Autoflex shafts in order of performance for my golf game, it would first be the driver followed by iron, fairway, and hybrid shafts. The driver shaft is simply like nothing I had ever used and has proven to be worth every penny. The rest of the shafts are honestly equally good, but in terms of cost and the amount of use during a round, I figured that iron shafts are the better value.

So is Autoflex the answer for all? Of course not. No single product can possibly satisfy the countless number of unique golfer swings in the world. The price of the shafts alone would be a big pill to swallow for most golfers, and the gains may not be enough to justify the cost for some.

But as high-end club manufacturers have shown recently, more and more consumers are willing to pay for products that provide real-world performance. At the end of the day, it’s up to each individual to decide where price and performance intersect for their own budget and golf game.

Moreover, the Autoflex shaft taught me that we may be missing out on playing better golf, simply because we take certain notions in golf to be true without really questioning them. To be sure, I never believed that a more flexible shaft could be both longer and straighter, but I am more than happy to be proven wrong. For me, the Autoflex shafts truly delivered what it promised, and stands out among the dozens of “game-changer” products I have tried over the years.

Lastly, I hope the story of the Autoflex further helps to encourage all golfers and manufacturers to re-think and reexamine other previously-held notions in golf. For, who knows what other benefits we may be overlooking to take this amazing game to the next level?

How about it? What has been your game-changer of late?