ABSTRACT

A CFRP shaft for the golf club is laminated structure by carbon fiber prepreg sheets, and the characteristic of it is variable by the quality, placement and a pair of orientation angles of fibers. The CFRP shaft composed of a three axes fabric prepreg sheet has higher torsion and bending rigidity than that of a conventional shaft (“Normal” shaft) (Matsumoto & Nishiyama, 2000). Now, the golf club shaft composed of four axes fabric prepreg sheets, which will be called as “4-Axes” shaft in this paper, is used for further rigidity and lightness (Gakken, 2005). Many golfers take in the difference of the dynamic characteristic between “4-Axes” and “Normal”, even if the static characteristic is the same. But the quantitative evaluation is a problem in the design and the fitting of clubs.