Method for producing golf shafts of like flex

The method of producing a family of tubular golf club shafts having the same longitudinal stiffness profile and different weights, including the steps of:

• producing a first shaft by forming a first preselected weight of composite angle-fiber-and-resin material about a first portion of a selected taper profile to form a first core, and forming a second preselected amount of composite longitudinal-fiber-and-resin material around the first core to form a first shell of the longitudinal-fiber-and-resin material for determining the stiffness profile of the first shaft;
• producing at least a second shaft on a different portion of the same taper profile by forming a second, different preselected weight of composite angle-fiber material about said different portion of the same taper profile by forming a second, different preselected weight of composite angle-fiber material about said different portion of the taper profile to form a second core, and forming the same second preselected amount of composite longitudinal-fiber-and-resin material about said second core into a second shell, said different portion of the taper profile being spaced along the taper profile from said first portion to compensate for the difference in the second preselected amount of core material and maintain the same outside size of the second core to produce the same stiffness profile from the second shell.

A family of tubular golf club shafts having the same longitudinal bending stiffness profiles and incremental differences in weights, each of said shafts comprising:

• a shell of composite longitudinal-fiber-and-resin material having a preselected amount of longitudinal-fiber-and-resin material for producing said same longitudinal bending/stiffness profile in each shaft of the family;
• and a core of composite angle-fiber-and-resin material for producing torsional stiffness in said shaft and having a preselected weight of the angle-fiber-and-resin, the preselected weight of angle-fiber-and-resin material in each shaft of said family being different from the preselected weights in the other shafts of the family to establish the incremental differences in the weights of the shafts;
• the core of each shaft having an outside surface that is maintained substantially the same size to maintain the same size shell in each shaft.

A family of golf club shafts having the same longitudinal stiffness profile and different weights, each of said shafts having:

• a tapered tubular shell of composite longitudinal-fiber-and-resin material comprising a preselected amount of longitudinal-fiber-and resin material and the same size for producing the same longitudinal stiffness profile in each shaft;
• and
• a tapered tubular core of composite angle-fiber-and-resin material having the same outside size to support the shell of longitudinal-fiber-and-resin material, the cores of the shafts of the family of shafts having different weights of the angle-fiber-and-resin material producing different overall weights of the shafts of the family.