| 摘要 |
<p>PROBLEM TO BE SOLVED: To increase a carry by specifying flexural rigidity and torsional rigidity in the tip part and the grip side of a shaft using a fiber reinforced plastic, setting the flexural rigidity on the grip side slightly higher, and setting the flexural rigidity in the tip part lower. SOLUTION: Increase of flexture in the shaft tip part is effective in obtaining a blow angle advantageous to a carry, so that flexural rigidity in the tip part is set to be 2×10<6> kgf.mm<2> or less. As flexural rigidity is set to be 8×10<6> kgf.mm<2> or more in the position separated from the tip part, by 900 mm or more, flexture of the shaft in returning is suppressed and a constant swing can be performed. Desirably, torsional rigidity of the shaft tip part is set to be 1×10<6> kgf.mm<2> or more in the area within 200 mm range from the tip part, while the flexural rigidity of the shaft is set to be 2×10<6> kgf.mm<2> or less in the 200 mm range from the tip.</p> |
