Revolutionize the way
you play the Game



"Can a shaft be made to provide a repeatable and effective downswing transition for better IMPACT, DISTANCE, and BALL CONTROL?"

Our ground-breaking FreeFlex Technology all began with that single question. And in our search for such a shaft to make the game easier and more enjoyable, we looked closely at the time-old convention that a stiff shaft is more accurate, but at the expense of loss of distance. What we discovered may now change the game as we know it. 

At SJ Golf Engineering Lab, we have discovered that torque and flex can be independent of each other and that the trade-off between accuracy and speed need not be so. For example, we found a way to make a super light (38g) and flexible shaft (170 cpm) but with torque as low as 2.5, which is stronger than an extra stiff tour shaft. 

Further research and experimentation with FreeFlex Technology resulted in our revolutionary FF38 and FF45 Special-series shafts, which can help most golfers swing easier or harder while chasing the distance and accuracy that we all crave.

Then came our incredible CBT carbon bending technology in Oct. 2023. And with its unexpected revelations and advances, we believe that the golf shaft industry will never be the same again.


“We have developed a unique shaft to which the pronate and supinate principles have been applied by considering not only the swing toque acting upon the shaft; but also in considering the warping moment and bending torsional moment to optimize Impact and MOI.” 

Dr. Seung-jin Choi on FreeFlex Technology

“CBT technology involves bending or wrapping carbon in a certain way to control how stiff a shaft feels, independently of weight, flex, and torque.” 

Dr. Seung-jin Choi on Carbon Bending Technology

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