Tuesday, October 2, 2012

How Much Does Shaft Torque Affect Performance?

Shaft torque affects performance a little bit, but not nearly as much as does the shaft’s weight, overall stiffness design and bend profile design. And here’s why. The term “torque” is used to convey the relative, comparative amount that a shaft is designed to resist twisting in response to a specific force. If the Rules of Golf were to allow clubheads to be designed so that the shaft would attach directly in line with the clubhead’s center of gravity, shaft torque would be a non-issue. The reason is because what causes a shaft to twist is, 1) the downswing force of the golfer, 2) the fact that the shaft attaches on the very heel end of the clubhead, which means all the weight of the head sticks out in front of the shaft. With all the head’s weight sticking out there, under the force of the downswing that weight will elicit a twisting force on the shaft. The golf industry’s first experience with shaft torque came way back before the early 1900s when the predominant shaft material was hickory. Wooden shafts had very little resistance to twisting. In fact, a completely different swing technique was required to prevent wooden shafts from twisting too much during the swing. Golfers who are used to seeing torque measurements on today’s shafts between 2 and 5 degrees would be interested to hear that a typical hickory shaft has a torque of more than 20 degrees!! In fact, the biggest reason that steel shafts took over in the 1920s and wiped the hickory shaft off the face of the golf industry was their MUCH lower torque, which resulted in far more accuracy and control of the shot. The first steel shafts were much heavier than hickory shafts, but golfers were willing to deal with the downside of heavier golf clubs to get the far superior resistance to twisting that steel shafts brought with them. Next came the introduction of graphite and fiberglass shafts in the late 1960s and early 1970s. Heralded as a huge break through because they were much lighter in weight than steel shafts, early graphite shafts failed to gain much of a foothold because their torques were over 10 degrees. The companies that introduced the first graphite shafts really did not know how to make their shafts with a lower degree of torque. As a result, the first graphite shafts could only be used by golfers with a smooth, passive, totally non-aggressive swing tempo. And this realization is what led to the industry learning just how shaft torque works, and what had to be done before graphite shafts could gain a much larger following. Because most of the weight of the clubhead protrudes out there well in front of the shaft, the moment the golfer begins the downswing, that force causes the clubhead to exert a twisting influence on the shaft. The greater the golfer’s downswing force, meaning the more abruptly and more aggressively the golfer starts the club down, the more of a twisting force the clubhead will exert on the shaft. At its worst, a very strong, aggressive swinging golfer using a shaft with a torque of 6 degrees and higher can see the ball fly with a severe, low hook. This is because that much torque does not provide enough resistance to the twisting force that a golfer with a strong transition move and aggressive downswing tempo will generate. The reason that torque is not much of a fitting factor today is because the shaft makers all design the torque of their shafts to fall in line with the flex. Shaft makers know that the faster the swing speed of the player, not always but quite often with that higher swing speed comes more twisting force on the shaft. Hence you rarely ever see S and X flex shafts with a torque higher than 4 degrees. And typically for the R, A and certainly L flex shafts, the shaft makers design the shafts with a higher degree of torque. This is because the slower swinger puts less twisting force on the shaft and thus the shaft does not need to have a lower torque.

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