With 3,894 units sold (as of February 2017) and 193 models across 77 brands reshafted, the potential of this shaft is apparent. Even amateurs can use this shaft and drive like a pro. NEXGEN E.I.F. is a next-generation product that completely overturns the conventional notion of shafts.
Driving the ball farther requires making the head heavier or the club longer. But this creates a dilemma—it makes the club harder to handle and makes driving the ball harder for people who are having problems with driving distance. E.I.F. is the solution to that dilemma. Supportive of increases in head weight and club length, the shaft allows the club to respond in a way that matches the golfer’s swing tempo. To design a shaft that supports weight and length, we decided to leave the area where conventional kick points are located stiff. By itself, however, this is no different than typical stiff shafts. We therefore added an ultra-high kick point that allows even people who lack power to swing the club. Of course, other sections of the shaft are stiff, so the club can also be used by people who do have power.
Potential energy is stored at the top of the swing, then the energy of the club is released all at once in the direction of impact. The driving club head transfers a maximum of energy to the ball, delivering a solid, high trajectory.
Because the shaft does the work with E.I.F., golfers can enjoy nice, comfortable drives without going all in on their swings. The easier motion places less strain on the body and creates a clean swing with a consistent tempo. This results in an average head speed of two meters per second and a straight drive that is 20 yards longer (individual results may vary).
The ultra-high kick point creates potential energy at the start of the downswing, storing the club’s energy.
The stored power is released all at once.
Increased stiffness compared to conventional shafts launches the club head and prevents slicing due to a late swing.
Increased stiffness compared to conventional shafts makes it easier to strike the ball with a good follow-through.
Typically, a shaft’s kick point is located around 400 millimeters from the shaft tip, within a span of a little over one centimeter. These kick points are referred to as “low-kick,” “medium-kick,” and “high-kick.” However, E.I.F. shafts are designed with an “ultra-high” kick point that enables amateurs to utilize the full deflection of the shaft in their swings.
[ Flexibility Curve of an E.I.F. Shaft ]
|Age||Head Speed||Head Weight||Club Length||Grip Weight||Total Weight||Swing Weight|
|24 – 92||29 – 55 m/s||169.7 – 207.3 g||45 – 49 in.||25 – 50 g||257 – 309 g||D2 – E5.5|
This is data of people who have ordered E.I.F. shafts. For drivers alone, we have reshafted a great variety of clubs—193 different models. A single type of shaft supporting this many models would be unheard of with conventional shafts.
|Person with Fast Head Speed||Person with Slow Head Speed|
|Reshaft Examples||Mr. I from Fukuoka (age 54)||Mr. F from Ibaraki (age 80)|
|Head Speed||49 m/s||35 m/s|
|Head Used (Loft Angle)||Athlete Model (8.5°)||Average Model ( 10.5°)|
|Head Weight||203.1 g||189.6 g|
|Club Length||45.5 in. + 1 mm||47.25 in. – 1 mm|
|Grip Weight||45 g||40 g|
|Total Weight||304.5 g||287.8 g|
Flex is typically used to rate how easy a club is to swing and use. But the flex ratings specified by manufacturers only indicate the stiffness of the shaft itself. The true usability of a club is determined by several factors—including the way in which the head, shaft, and grip are fit together—so it cannot be understood through the conventional flex ratings.
While E.I.F. shafts do flex, we don’t specify a rating for them because they don’t conform to the traditional concept of flex: the area near the grip is more flexible than R flex, but the center portion of the shaft is stiffer than X flex (refer to the graph above).
Every shaft ordered is adjusted by the developer in units of 1 mm and 0.6 g so that even amateur golfers can feel the subtle differences swing weight makes on their trajectories. Details of all the adjustments made thus far are recorded in the developer’s notes.