To provide a shaft inhibiting an increase in a shaft weight, generating substantial whip for acquiring a large carry, where the whip felt by a golfer is not too much, and allowing the golfer to swing with a sense of security.
The golf club shaft secures appropriate whip and swing feeling, while retaining acceleration of a head and increase in a carry by the whip, by maintaining flexural rigidity as it is and improving torsional stiffness of a shaft tip end side principally. In concrete terms, a ratio GI(x)/EI(x) of the torsional rigidity GI(x) to the flexural rigidity EI(x) on respective points on the shaft is defined to 0.5 or more and 1.0 or less. Alternatively, a value of a ratio GIa/EIa of an average torsional rigidity GIa to an average flexural rigidity EIa is defined to 0.6 or more and 0.9 or less.
TAKIZAWA HIROKI
SASAKI YASUSHI
