Mizuno Corporation

Yasushi Matsui

Hiroki Ashida

Goro Hisamatsu

The golf club shaft comprises a reinforced tip portion from the tip end to the position 300 mm toward the grip end, gripping butt portion from the grip end to the position 100 mm toward the tip end, and an intermediate portion between the reinforced tip portion and the gripping butt portion. The shaft satisfies an equation EI&equals;&agr;&middot;X at its intermediate portion, where EI (Nm ) is the flexural rigidity, X (mm) is the distance from the tip end of the shaft, and &agr; is a given constant. The &agr; values of the shafts in accordance with the embodiments 1 through 3 are 0.12, 0.09, and 0.06, respectively. Thus, the present invention has an improved deflection during downswing and is liked by a majority of players.

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Gifu, Japan

Yasushi Matsui