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Mystery Shrouds South Korean Shaft

Not much is known about the AutoFlex shaft made by the South Korean company Dumina other than there is a hefty cost to be paid for big gains in distance. Count Morning Read contributor Gary Van Sickle as being sold on the results — and price tag.
While a lot is not known about the AutoFlex shaft, it features a soft composition, weighs between 41 and 75 grams and is available in five specifications based on clubhead speed.  

While a lot is not known about the AutoFlex shaft, it features a soft composition, weighs between 41 and 75 grams and is available in five specifications based on clubhead speed.  

This is not an advertisement, this is a serious question: What would you pay to gain 8, 10 or even 15 yards of carry distance with your driver?

The correct answer for many golfers, especially aging seniors such as myself, is practically anything. Within reason, of course.

A hot new mystery shaft from South Korea pushes those boundaries of reason. It’s called AutoFlex. It sounds too good to be true and is counterintuitive to what we thought we knew about driver shafts — shorter, whippier and less-lofted can mean longer and straighter drives.

So is $780 within reason? That’s the price of the AutoFlex shaft. If that price is too rich for your blood, you can stop reading right now unless you care about the punchline: AutoFlex works even if it sounds like a Ripley’s Believe It or Not item.

I’m a believer, as are many other documented online users, along with a gaggle of pro players who have tried it, are working with it (Adam Scott, Fred Couples and Michelle Wie West have been photographed with the shaft) or have used it in competition (Louis Oosthuizen, final round of the Masters; Branden Grace, PGA Championship). If you’re watching at home, look for a pro wielding a shaft that’s hot pink on the top half and black on the bottom half. Those are AutoFlex’s colors.

AutoFlex, made by a company called Dumina, is shrouded in mystery. On the company’s website,, the headline accompanying the shaft photo says “Korea Hidden Technology.” The part about the shaft being a mystery will stay that way for now.

The company said it will not file for a patent on its manufacturing process. It seems like a shrewd move given how patent, trademark and copyright laws are ignored in Asia. A patent would be a blueprint for illegal copycats. Instead, competitors will have to reverse-engineer whatever Dumina has done, if they can.

So I can’t tell you how or why AutoFlex works. I can’t even tell you why it should work.

You will be skeptical about the next part, and rightly so. The AutoFlex shaft is soft. Very soft. And it is ultra-lightweight, from 41 to 57 grams, depending on the model. What happens during the forward swing acceleration that makes it perform? The mystery deepens.

“What’s funny is, the shaft is so soft, it whips all over the place when you wave it yet somehow it returns at impact to make the ball go straight,” said Joe Corsi, a consummate clubfitter who runs Corsi’s Indoor Golf in Greensburg, Pa. “I’ve never seen anything like it.”

Corsi is responsible for getting me into an AutoFlex-shafted driver. Corsi is a good senior player with street cred. He and I played in the same U.S. Senior Amateur a few years back.

This mystery started when a YouTube review of AutoFLex by Ian Fraser and Matt Blois of TXG (Tour Experience Golf), a Toronto-area clubfitting store, caught Corsi’s attention. Fraser, who is CEO and founder of TXG, is known for data-driven, unbiased equipment reviews. Blois is a lefty and a power player whose clubhead speed is normally around 122 mph, exactly the kind of guy who doesn’t need a few extra yards and whose muscle figured to turn the soft AutoFlex shaft into sprayed drives in all directions.

Watch the review. Blois' first tee shot went 353 yards, in the fairway. The next went 374 yards, also in the fairway. His clubhead speed rose to 127 and later, with different weights in the driver head, to 130 mph while his ball speed — the number that really matters — jumped from 170 mph to 180.

“Not only was I impressed with Matt’s speed gain,” Corsi said, “they were raving about how straight the ball went.”

Though skeptical, Corsi ordered some shafts, fitted a few drivers and had some friends who were pretty good players try them out.

“We saw the same thing as the TXG video, with ball speed jumping up seven, eight, ten miles an hour,” Corsi said. “That equates to about 1.5 yards per each mph.’

The 10 shafts Corsi ordered as an experiment — an expensive experiment —sold out within two weeks. Four months later, he has sold more 200 AutoFlex-fitted drivers, and a few 3-woods.

Through trial and error, Corsi has demystified a few things. To work its best, a driver with an AutoFlex shaft needs a light swingweight of D-1 or D-0. Instead of going longer with the shaft to increase distance, AutoFlex works better at shorter lengths of 45 to 45.25 inches. It has a higher launch angle, too, so Corsi usually reduces the loft for customers — from 10.5 degrees to 9.0 degrees for me. He found that AutoFlex works well with the current Callaway, Titleist and TaylorMade models, while Ping heads require extra adjustment because they’re slightly heavier.

“Look, I only sell things I believe in,” Corsi said. “I’m a believer. I’ve had people tell me, ‘It’s smoke and mirrors.’ Well, it works for me and it’s worked for almost everyone who’s tried it. I went out on a 50-degree day here and hit it to places I haven’t reached in a long time.”

Corsi fit me on a launch monitor in his store on a day when I was fighting a reverse-pivot pull-hook, probably because I was trying to make my old-guy clubhead speed numbers look better. The best I could do with my Titleist TS2 driver (Titleist’s previous generation) was 230 yards of carry on the launch monitor. Using a new TSi3 and an AutoFlex, I consistently maxxed out at 240 yards.

That’s just launch monitor dreaming, you say? In my first round using the AutoFlex, I reached both par-5 holes in a nine-hole golf league (or would have if my second shots had been straighter), something I hadn’t come close to doing before. The ball also runs out on the ground a little farther with AutoFlex, it seems, possibly due to a lower spin rate.

I believe the launch monitor numbers. I have picked up 10 to 12 yards in the air, no doubt, on a good swing. That might be enough to get me back into a few local amateur senior tournaments. My bad swings? They’re still bad swings. Some of Corsi’s customers have come back to get an AutoFlex in their 3-woods, too.

The AutoFlex shafts come in five specs, based on clubhead speed. The 305 is for swing speeds of 70-85 mph; 405, 85-95 mph; 505, 95-105 mph; 505 X, 105-115 mph; and 505 XX, 115 and above. Corsi slotted me in at the 505, even though my clubhead speed is slightly below that.

The only negative I’ve heard about AutoFlex came from a Pittsburgh-area senior club pro who told me he was probably going to take it out of his bag after using it for a few weeks. Why, I asked? “I’m hitting it all over the place,” he said. “I think I’m swinging too hard … because I can.”

My AutoFlex tryout went too well to pass up. I had to buy the pricey shaft and the Titleist head, which meant buying the whole driver, too. My bill was $1,325. I swallowed hard, but wrote the check. I have no regrets.

Korea’s Hidden Technology, whatever it is, works for me. Is AutoFlex worth $780? Well, that’s your call.