A Lesson In Golf Shaft Torque Values
What is shaft torque?
It is the amount a shaft twists when subjected to a known amount of force (usually one foot-pound of force is applied) and the value expressed in degrees. It is a term commonly associated with composite or graphite shafts, but steel shafts have a certain degree of torque too. However the amount cannot be independently changed from the frequency (or stiffness) of the shaft like a composite design, thus torque of steel shafts is generally not mentioned. A low torque value (i.e. 3.5° versus 4.5°) resists the shaft from twisting on the downswing.
What causes the shaft to twist?
During the motion of the swing, the clubhead automatically begins to exert a twisting influence on the shaft. This natural twisting force is created due to the shaft attachment point in the heel area of the clubhead. The center of gravity of the clubhead is in the middle (or approximately) of the head and therefore is not in line with the shaft. Under the force of the swing the head has a tendency to rotate about its own center of gravity and thus try to twist the shaft.
The one thing about torque is that it is perhaps the most mis-understood shaft parameter and to the bewilderment of many, may not make complete sense. A case in point is was a potential shaft design that I had a recent opportunity to test and evaluate for a certain shaft manufacturer. This is one of the spoils of being the technical director, but someone has to do it. I am never at a loss to test new models, especially if the shaft is unique to the market.
A New Shaft Design and Experience
This particular shaft model, which I will remain nameless until it is available for sale, had some very unique specifications that I had not encountered on a shaft before. One of the samples had a torque value of over 9°, another at 7° and another above 6°. Before we go any further, one thing to know is that there are no industry standards on how torque is measured. While almost all manufacturers use 1foot-lb of force, the amount that the butt and tip ends are clamped varies. The distance between these clamping positions is called the “beam length”. All the testing I have done for the past 19 years, I typically measure a greater beam length than all manufacturers, so the torque values I have provided will always be higher than when the manufacturer publishes their specifications.
One of the common myths about shaft torque is that a lower value will result into a straighter shot, especially for golfers with higher clubhead speeds like me. One of the reasons shafts with higher torque values are considered less accurate can be attributed to cost. Often times the higher torque wood shafts (above 6°) will be less than $9 retail and may not be 100% graphite, but have a certain percentage of fiberglass mixed in. Some shafts that are found in boxed sets or very inexpensive composite shafts contain fiberglass. One hint if it does – look at the published weight. If it is heavy with a high torque value, then it will have a high percentage of Fiberglass.
Low cost graphite shaft are constructed with low modulus (or lower strength) materials. Often times these shafts will exhibit both high torque and a softer tip section. In the hands of a stronger player, I would concur that a shaft with this combination would be less accurate than a lower torque model. This statement is based on player testing over the years. Now these shafts I was testing did not have any fiberglass, but I did not know at the time what material was used in the construction of the shafts. It wasn’t until I hit them and I provided feedback to the manufacturer that I became aware. I all I knew was several parameters I carefully measured, including the higher torque value.
There Is No Substitute For Human Testing
Often times one can get caught up in the numbers and form a bias or stereotype before even hitting something. I didn’t want any of the running through my head when I was out field testing the test shafts, but it was difficult knowing ahead of time what I had tested. To my complete surprise, I didn’t see any more inaccuracy from shot-to-shot as I would with expensive, low torque models. No hooking or slicing occurred that many golfers might suspect based upon torque information alone. This even included one particular sample that was over 9° and had a frequency that was the equivalent of a flex softer than a traditional L (ladies) flex. Does this mean I need to start wearing a skirt and high heels next time I go out?
Granted these shafts were tested in Hireko’s best driver designs and we claim that you get incredible accuracy. So I went out a second day at the range armed with the same shafts, but in different Hireko drivers to prove / disprove the results were not a fluke. So all these years I have been telling customers that higher torque shafts for stronger golfers will likely lead to inaccuracy problems gone out the window with two large buckets of balls, plus handing the clubs to some unsuspecting fellow range rats that are always happy to hit something new.
Does Torque Affect Feel?
Another myth or common belief is low torque shafts feel firmer while high torque shafts feel more flexible. I can honestly say these were not flexible as the torque value would indicate. Torque is yet of a handful of different parameters that control the feel of the clubs. Torque by itself is not the culprit of the feel it is more likely a result of the stiffness distribution of the shaft created by the fiber alignment and the modulus of material used in the construction of the design.
As I stated before, these had a very unique set of specifications that I had not encountered on a shaft before. These three shafts had a very firm tip section for any shaft that had near as high a torque value. As a later found out these were made using a high modulus material. The stiffer tip section coupled with the higher modulus material (possibly causing a faster recovery time) created relatively straight /consistent shot pattern; not the inaccuracy of higher torque valued shafts in the past made from less sophisticated raw materials.
Composite shafts can be made with the same frequency (flex), but feel completely different. Here are the four extreme categories that a shaft could fall into and some notes to help explain what you might feel or experience:
Stiff Tip / Low TorqueFirmestLowest or perhaps a fade bias
Stiff Tip / High TorqueFirmNeutral to perhaps a slight fade bias
Flexible Tip / Low TorqueMediumNeutral to perhaps a slight draw bias
Flexible Tip / High TorqueSoftestHighest or perhaps a draw bias
You can see a complete list of detail shaft specifications in Hireko’s 2008 Shaft Fitting Addendum
Why You Should Adopt My Mantra
In the end it is simply best to have an open mind when trying a new product. You may be pleasantly surprised that something on paper you may never have tried actually works quite well for your game. There are many myths that have been passed down regarding shaft fitting. But as new materials and designs become available, some of these myths can be debunked. That is why my new mantra is “Shut Up and Just Hit the Ball”. The worse thing is it may confirm a suspicion, but it can also lead you to finding that one thing that can make the game more enjoyable and lower your score.