To obtain a composite shaft having the position of the center of gravity at the central part thereof along the length of the shaft by providing a thermally hardened layer tapered, made up of a unhardened rectangular thermosetting resin prepreg sheet produced by arranging a long fiber parallel with the long side thereof in the direction of the fiber.
A rectangular prepreg sheet 3 produced by arranging a long fiber 2 parallel with the long side thereof is wound on a mandrel 1. At this point, the prepreg sheet 3 comprising an unhardened thermosetting resin is made rectangular. Then, the rectangular prepreg sheet 3 is wound to be hardened thermally to manufacture a composite golf club shaft with the center of gravity shifted to the tip side thereof. The rectangular prepreg sheet 3 may be used in either a bias layer or a 0° layer. All or a part of the plurality of layers may be made up of the rectangular prepreg sheet 3.
MATSUMOTO AKIO