Shafts...The Engine of the Club

by Frank Thomas

A lot of people get very concerned about what make and model of club they should be using. But perhaps the most important piece of equipment is that oft-overlooked bit between the grip and the head -- the shaft. The shaft is the only way energy can be transferred from the golfer to the business end of the club, the clubhead.

During impact, the shaft is unnecessary -- its only use is to get the clubhead into the proper position, traveling on the right path and at the required speed just before impact. Remember that impact, when the club and the ball are actually in contact, only lasts for approximately 450 millionths of a second. When the shaft decides to react to a mis-hit the ball is long gone, so it plays no part in reducing an error, contrary to what is sometimes believed.

The shaft used to be a stick of hickory that was turned in a lathe, shaved and sanded down by hand. This allowed shafts to be custom-made exactly how the golfer or the club maker wanted them. Through trial and error, the best shaft-makers became very adept at producing high-performance hickory shafts. With the advent of steel shafts (approved by the USGA in 1924 and eventually approved by the R&A seven years later), mass production took over and the days of modifying custom shafts were over. The good news is that quality control is so good nowadays that there aren’t many bad shafts any more, but there are hundreds of different varieties.

And there is still room for some innovation. Shaft manufacturers have tried everything. They’ve moved the flex point higher to produce a lower ball flight. They’ve moved it lower to produce a higher ball flight. They’ve even turned the shaft upside down, with the most flexible part of the shaft under the grip, and the least flexible section down near the head.

Inevitably, there has been a lot of experimentation with different materials for shafts besides steel. Before I joined the USGA, I worked as Chief Design Engineer for the Shakespeare Sporting Goods Company from 1966 to 1974, where I developed the first graphite shaft. One company had started producing shafts made up of a thin steel tube wrapped with a layer of fiberglass, but in the early 1960s, Shakespeare became the first company to introduce a complete fiber glass shaft. These shafts were really strong, but too heavy, and they didn’t have good torsional properties. Steel remained as the old standby while manufacturers continued to innovate. Along came aluminum shafts that were much lighter -- this was supposed to be a revolution in golf, the hottest new thing. Suffice to say, aluminum shafts only lasted a few years.

Union Carbide had been providing graphite fibers -- 50 of them bundled together make up a strand the size of a human hair -- for use by NASA, which had started to use graphite in the space industry, and for use in pressure vessels, and structural sections of aircraft. Union Carbide wanted to introduce graphite to a consumer market, and considering its strength and lightness -- it’s 14 times stronger than steel of the same weight -- golf club shafts seemed like a good bet. So they approached me, and Shakespeare, as I was developing new techniques to filament-wind golf shafts using fiberglass. They asked if graphite fibers could be a substituted for the glass fibers. Material properties had to be researched, but the application was eventually successful. The technique was to wrap epoxy impregnated bundles of fibers onto a thin steel rod. This was in turn wrapped with a cellophane sheath and then hung in an oven to cure and set. When the epoxy set the central steel rod (mandrel) was withdrawn, leaving a hollow shaft made of graphite fibers and epoxy.

The first graphite shafts -- circa 1968 -- were tested by players like Don January and Gary Player, and they officially debuted at the 1970 PGA Merchandise Show. Due to some technicalities regarding time between disclosure and filing, the patent wasn’t granted, which means that now anyone is free to make graphite shafts.

What are the benefits of graphite? It’s much lighter than steel -- the shaft is just over two ounces, about half the weight of a steel shaft. That means it may be possible to swing the club a little faster with the same energy, and thus one may be able to gain about five yards of distance on average. There are other claims for graphite -- that it allows you to "feel" the clubhead more, for example, or that it is easier on your joints, reducing the risk of golfers’ elbow -- which may or may not be true. The only downside is that it’s still expensive. In 1968 the costs were $500 for a pound of graphite, compared to 30 cents for fiberglass and 7 cents for steel. Titanium was tried as a substitute for steel and graphite about 10 years ago but never took hold. It weighed more than the graphite but less than steel but was also very expensive.

Is graphite the end of the line as far as shaft material is concerned? It might be. Other hybrids were used mixing graphite with Kevlar, boron, or steel fibers, but I believe no other material offers the combination of lightness and strength that graphite has.

Is this the end of the line in shaft innovation? No, but we don’t expect much is in the wings where the weight- (or even cost) to-benefit ratio will be worth the effort.

Today, most every good fishing rod is made of graphite, as are plenty of tennis rackets and a lot of golf club shafts. I would like to think that eventually, when the price comes down enough, practically all golf clubs will have graphite shafts.

When you see all the different shafts on the market, with variations in such things as material, shape, length, kick point, swing flex and color, you might conclude that club manufacturers have free reign. But in fact, there are some specific regulations about what a club shaft can and cannot be, particularly in Appendix II of the USGA’s rulebook, which addresses three aspects of a shaft: Straightness; Bending and Twisting Properties; and Attachment to Clubhead:

1. Straightness
The rulebook says: "The shaft shall be straight from the top of the grip to a point not more than 5 inches (127 mm) above the sole, measured from the point where the shaft ceases to be straight along the axis of the bent part of the shaft and the neck and/or socket."

My elaboration: Shafts have to be straight. Simple, right? Not entirely. How straight is straight? The fact is, I’ve never seen a truly straight shaft -- every one has imperfections that prevent it from being 100 percent straight. But, as with so much law, what’s important is intent: the intention of the rule is clear. If you try to make a shaft that isn’t quite straight so as to confer an advantage on the golfer, obviously that’s a violation. If you intend to make a shaft that’s straight but it ends up in the manufacturing process being a couple of microns away, that’s fine.

2. Bending and Twisting Properties:
The rulebook says: "At any point along its length, the shaft shall: i. bend in such a way that the deflection is the same regardless of how the shaft is rotated about its longitudinal axis; and ii. twist the same amount in both directions."

My elaboration: In the late 1950s, a rule was adopted that a shaft had to be circular in cross-section. But in 1984, there were a lot of rule changes, and that was one we threw out. Why? Because we decided that what was important was not the shape of the shaft, but its bending and twisting properties. For instance, it would be perfectly possible to build a composite shaft that is circular in cross-section, yet bends differently in different directions, or twists different amounts clockwise compared to anti-clockwise, and there could be playing benefits to such a shaft. So now shafts don’t have to be circular in cross-section -- theoretically it would be perfectly legal for someone to build a shaft that was square in cross-section (imagine the marketing possibilities of a putter with a square shaft), just as long as the shaft doesn’t have any irregular bending or twisting characteristics.

3. Attachment to Clubhead:
The rulebook says: "The shaft shall be attached to the clubhead at the heel either directly or through a single plain neck and/or socket. The length from the top of the neck and/or socket to the sole of the club shall not exceed 5 inches (127 mm), measured along the axis of, and following any bend in, the neck and/or socket. Exception for Putters: The shaft or neck or socket of a putter may be fixed at any point in the head."

No elaboration required here, although I will say the latter exception for putters allows for all kinds interesting, innovative designs, which is a good thing. Besides these provisions, there are a couple of umbrella clauses in the rules -- and some shafts that dance around the line of acceptability. For instance, Rule 14-3, says in part that "the player shall not use any artificial device or unusual equipment." And Appendix II includes this line: "The club shall not be substantially different from the traditional and customary form and make."

So a shaft with an aerodynamic foil attached would not be permissible. Similarly, a few years ago a company came out with the Whisper shaft -- it had a coil wrapped around the outside of the shaft, similar in appearance to an antenna on a car aerial. The coil reduced drag, and the swishing sound of the club cutting through the air was greatly reduced. As a result, the shaft may have caused a very small increase in clubhead speed, but, alas, such a coil is certainly "unusual" and not "traditional and customary." It was banned.

What about composite shafts? There had been many shafts in the past with multiple materials throughout the entire length, but about 10 years ago a company introduced something new: a shaft where one section was steel and another section was graphite (like the new BiMatrix shafts from True Temper). Personally, I was against such shafts -- I’d say they don’t remain true to the umbrella clauses, above. But they were approved.

Of course, you cannot have a rulebook that covers every possible specification, which is why clubs are submitted to the USGA for approval. But there’s a lot of room for innovation and customization. If you want your shafts to be, say, bubble gum pink, there is absolutely nothing stopping you, except the ridicule of your peers.

But perhaps the most important aspect of any shaft is making sure it has the right flex -- for you. A broomstick is too stiff, a fishing rod is too whippy -- you want to shoot for something in the middle. The best way to find what works for you is trial and error. But keep in mind that most people aren’t as strong as they like to think they are, and thus most golfers have shafts that are too stiff for their swing speeds.

The bottom line is that the shaft is the only means of transmitting the energy to the clubhead from your body, so it better feel comfortable to you. Only trial and error will get it right. Start experimenting with the more flexible shafts, then move toward the stiffer ones, rather than the other way round. Don’t let the macho thing influence you in trying to make a stiff shaft work. It does not mean that you are suffering from a lack of testosterone if a more flexible shaft works best for you.