As players of all abilities have learned that golf shafts are one of the integral pieces to the golf-club-performance puzzle, more companies have entered the market with high-end shafts. Consumers have accepted the high price points and buy shafts based largely on what they see being used by the top players on the professional tours. Many average-playing consumers can’t see or often understand the differences among shafts, and to most of them a shaft is just a pretty-colored stick of graphite that they buy depending on if they see their favorite player using it.
While there have been significant advancements recently in material and process technologies, the basic rules of composite golf shaft design still and will always apply. There are only a few basic ways an engineer can measurably alter the flexural characteristics of a composite golf shaft. These design parameters include geometry, fiber type, amount of fiber and fiber orientation.
Geometry or shape contributes to the shaft’s stiffness. A larger diameter shaft is stiffer than a smaller diameter shaft both in bending and twisting. By varying the diameter at different locations along the length of the shaft it’s stiffness can be manipulated.
The type of fiber is also critical to achieving the desired flexural properties. High modulus graphite is stiffer than mid or standard modulus. Therefore, a shaft produced with higher modulus material will be stiffer.
As the amount of fiber in a shaft increases, the shaft becomes heavier and stiffer. Stiffer flexes within a shaft model tend to be slightly heavier than the softer flexes because the shaft designer is simply applying more fiber to reach the stiffer flexes.
Perhaps the least intuitive to the non-engineer is fiber orientation. A shaft’s flexural properties can be manipulated by varying the angle of the fiber along the shaft’s length. Fiber running directly down the shaft gives the shaft its bending stiffness. Fibers at 45-degree angles to the shaft’s centerline give the shaft its torsional or twisting stiffness. Fibers at 90 degrees or around the shaft offer hoop strength. All golf shafts are designed using multiple layers of fiber run at various angles to achieve the desired flexural properties.
Aerotech’s engineers have determined that hoop-oriented fibers are a very critical part of a shaft’s design and performance characteristics. Hoop strength holds the shaft round when it is deflected, and keeps it from deforming during the swing and at impact. Hoop fiber was originally used to improve the durability of a shaft by preventing it from deforming, but Aerotech’s engineers have discovered that this fiber orientation also influences the playability of the shaft. If a shaft does not have adequate hoop strength it will become unstable during the swing, creating unwanted oscillation of the clubhead. The makes it very difficult to make consistent contact with the ball
Aerotech’s SteelFiber ™ shaft offers the performance benefits of both Steel and Graphite in one shaft. It has over 59 miles of steel fiber oriented in the hoop direction around a graphite core. The SteelFiber shaft holds its shape better than conventional graphite and steel shafts, making it a more stable and consistent shaft. The shaft’s graphite core dampens vibration and increases clubhead speed, while the steel fiber surface layer provides stability and control. This fiber orientation is now an integral feature of Aerotech’s SteelFiber and Players Spec shaft designs, offering graphite power and steel stability.
Jack Nicklaus has used the SteelFiber shaft in his hybrids, and Retief Goosen used a driver shaft – neither was paid to do so. That’s a pretty strong endorsement.
“Last year…I was looking for a composite shaft that had the performance characteristics similar to the Dynamic Gold steel shafts I play in my irons,” Nicklaus said. “I found that performance with the SteelFiber shaft.”
Other companies have put metal into graphite, but it’s generally been in the tip section to help reinforce the shaft. It hasn’t really done anything effectively in terms of achieving the playing characteristics of both steel and graphite in one shaft.
“What we’re doing is adding the stability and control of a steel shaft by applying steel to the entire surface of a graphite core,” said Chris Hilleary, president of Aerotech Golf. “The steel layer adds “Hoop Strength” and increases the shafts MOI giving it playing characteristics previously unattainable in a 100% graphite or 100% steel shaft”. Benefits of SteelFiber technology
Power of graphite with the stability of steel
Graphite core for vibration dampening, increased clubhead speed and maximum distance
Steel fiber covers the entire surface for adding stability and control for pinpoint accuracy
Optimum weighting without increased wall thickness for a solid feel through impact
Perimeter weighted for higher shaft MOI resulting in greater forgiveness
Originally developed for irons the SteelFiber technology is now also available to enhance the performance of hybrids, fairway woods and drivers. General construction of SteelFiber shaft
High modulus graphite core
Over 59 miles of steel fiber covers the entire surface of each shaft
Each steel fiber has a diameter of 8 microns, approximately 1⁄10th the diameter of a human hair
The new Player Spec™ iron shaft, designed to improve the playability of composite shafts for stronger players, is constructed with Aerotech’s SteelFiber technology and features an “ascending mass” design so each shaft within the set gets heavier as it gets shorter. This promotes easier to hit, lighter weight long irons and more controllable short “scoring” irons. In addition, the ascending mass creates a more balanced moment of inertia (MOI) in every club throughout the set giving the player more consistency from club to club. Players Spec Benefits
• SteelFiber Construction
• Ascending Mass Design
• Easy to hit long irons
• More controllable short irons
• Balanced MOI About Aerotech Golf LLC
Beginning production of Golf Shafts in 1994, Aerotech was able to take advantage of its vast knowledge of composites and a proprietary manufacturing process to create one of the most innovative and consistent golf shafts ever made. Originally operating as an OEM supplier, Aerotech produced shafts for companies such as Cleveland Golf, Adams Golf, Lynx, Zevo and Pure Spin. By launching its own branded golf shafts in 2002, Aerotech has become known as a producer of some of the most innovative, high quality golf shafts on the market. www.aerotechgolfshafts.com