More on shafts
4/20/01
Last week I wrote about shafts and all the different materials they have been made with over the years. 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. I’ll talk about those in next week’s column.
This column appeared on golfdigest.com where Frank contributes on a weekly basis. Check it out every Saturday.