Technical Tips

October 2008

Shaft Facts

Thoughts from:
Jeff Jackson author of Total Club Fitting in the 21st Century,
Tom Wishon author of Common Sense Clubfitting,
Lori Rice at UST United Sports Technology
and Jacques Lemoyne Certified “Class A” Clubmaker

FLEX – This is the most often used word to describe a shaft.   A shaft produced by one manufacturer may be very different than a shaft with the same designation produced by another company.   Instead of relying on a random letter on a shaft, flex can be more accurately measured with a frequency analyzer.  Flex does have an effect on the clubs performance.   The shaft is designed to bend and unbend, load and unload.   The proper fitting shaft will store the energy of the swing and release the energy to obtain maximum impact with the club head in a square position.   A shaft that is too stiff will limit the amount of energy stored, causing low ball flight and lack of feel.   A shaft that is too soft will unload too early, making it difficult for the club head to be square at impact.

WEIGHT – Shaft weight has a direct relationship on how fast a club can be swung.   Faster swing speeds can result from lower overall weight and/or give you the ability to build a longer club for more club head speed to yield more distance.   This is a give and take. Longer clubs, or too long of a club, usually cost you some accuracy.   Lighter weight shafts may be swung faster, a plus for older players, ladies or those who lack swing speed or strength.   The shaft weight affects the golfer’s feel.   Too light of a feeling club (lack of feel) results in a decreased ability to hit the ball on center and/or the face of the club may be open or closed.   Too heavy of a feeling club will not let the golfer generate a high enough club speed to maximize distance and result in a higher number of off-center and/or miss-direction hits.

TORQUE – Torque is the amount of rotational twisting occurring during the swing.  The traditional way to measure torque is to clamp the butt end of the shaft and support the body of the shaft.   A bar is attached to the shaft tip and a given weight is suspended from it.  The deflection or twist is measured in degrees.   Torque does have an effect on the club’s face angle at impact.   Proper torque will return the club to a square position at impact.   Too much torque will close the club face at impact (pull) and too little torque will leave the club face open at impact (slice/push) or pull/hook if the golfer has an early release.   Feel is also affected by Torque.   Average golfers benefit from a Torque of 4 degrees or above.   Strong golfers, club head speed above 100mph, benefit from Torque below 4 degrees.   Currently, the lowest Torque shafts are around 2 degrees.   Even the best golfers, with the best hands, lose feeling around 1.8 degrees of torque.   The rule of thumb for slower swinging golfers to stay away from shafts with to low of torque, is not done to prevent miss direction hits, but for feel.   The lower the torque of the shaft, the more “stiff and boardy” the shaft will feel when hitting shots.

BEND POINT – Bend point has a marginal affect on ball flight, but more on feel.  The Bend Point of the shaft may change the ball flight 2 yards higher or lower.   Club head loft and Center of Gravity have more influence on ball trajectory.   Bend point is a by product of the stiffness distribution of the shaft and has an effect on feel.   Lower Bend Point shafts provide a softer feel than mid or high bend points.  

TIP – Bend Point has a direct relation to Tip Stiffness.   A high bend point shaft will typically have a stiff tip and a weak butt.   A low bend point shaft will have a soft tip and a firm butt end.   The tip stiffness (or lack of) may help the golfer.   A softer tip shaft may allow the shaft to bend more into a closed position at impact, reducing a slice.   A stiff tip could have the same effect for a hook.  UST says tip stiffness has an effect on ball spin …. “Typically, a softer tip shaft does help launch the ball higher but it may also increase ball spin if the butt end is not firm enough.  So we have created the AXIVCore for tighter, lower spinning high launch shaft.  A firmer tip shaft helps with control and lower launch.”

CONCLUSION – These are specific characteristics that manufactures and Clubmakers are able to measure.   These numbers are a way to compare shafts on paper. Other factors that affect the performance of the shaft are:
          Total length.
          Total mass.

The Center of Gravity off set of the club head.
          The mass of the club head (head weight and distribution of weight).
          The acceleration of the club by the golfer.
          The backswing to downswing transition.
          Wrist-cock release.
         
….. and more. Be patient during the process of being fitted. The shaft needs to fit you, your swing.