Shafts are constantly changing as technology evolves
At seahorse designs we use launch monitors and ball flight simulators to select the shaft that will produce the best performance for your golf swing we supply all shafts from standard steel through to prototype tour editions.
Bend angle, as measured by total shaft bend, shows a shaft’s contribution to Launch Angle. Simply stated irons have significantly less shaft bend than woods. As will become evident, the closeness of irons’ CG to their shaft centrelines and their relatively short shaft lengths are the reasons for the difference in shaft bending when compared with woods.
A shaft will bend during the downswing, at impact it will typically be bending toward the ball. This bending increases the effective loft of the clubhead, such that a one degree increase in bend angle is equivalent to a one degree increase in club head loft. The shaft bending can actually be away from the target for some golfers with strong aggressive swings. The clubhead will be lagging the shaft at impact.
There are two forces effecting shaft bending; the first is due to centrifugal acceleration and the second due to radial/tangential acceleration.
Centrifugal acceleration is created in the swinging of the golf club in much the same way as an object moves outward when swung around at the end of a string. This acceleration produces a force on the head equal to the mass of the head times the head velocity squared divided by the radius of the circle on which the club is swung around the body. For the purpose of actual calculation, the radius can be measured from the bottom of the golfer’s throat to the CG of the clubhead in the address position. Because the head’s CG is behind the shaft centreline, this creates the potential for a force to act on the head CG and creates a twisting torque which changes the dynamic loft angle during the swing. This torque bends the shaft forward and downward thus increasing the loft angle of the clubhead at impact’ and the downward droop of the shaft. The further back the CG, the faster the clubhead speed, or the more flexible the shaft tip, the more the bend. The shaft can at most, bend forward by the distance from the head CG to the shaft centreline. For example, if Tiger Woods swung an ‘L’ flex shaft, he could still only generate this type of bend to the depth of the CG behind the shaft centreline.
Radial or tangential acceleration of the head occus as the club is accelerated by the golfer at the beginning of the downswing. For example, when the golfer starts the club down from the top of the backswing, the shaft responds by bending with the mass of the head causing the head to lag behind this bending action of the shaft. The bending which occurs during the early part of the swing is normally dissipated before impact and plays little role in the loft angle. For the typical golfer, the only bending that effects launch is due to centrifugal acceleration. However, if a golfer is strong enough, particularly with the arms and wrists, it may be possible to influence the launch by means of continually applying tangential acceleration through the entire downswing. However, this normally will only happen with very strong golfers who are able to retain the wrist-cock until very late in the downswing.
The effect of tangential acceleration can be either positive or negative on the shaft. If the head is still accelerating (gaining speed) just before impact, the shaft will bend backwards (shaft lag) thus reducing the loft and offsetting the effect of centrifugal acceleration which always wants to bend the shaft forward before impact. If the golfer slows the club and losses tangential acceleration before impact the shaft will bend forward (shaft lead) and increase the launch angle. This latter case is much more prevalent.
Here is a small selection of the shafts on offer