A golf club shaft includes: a butt end; a tip end, where the golf club shaft is tapered between the butt end and the tip end; coils of fiber wound helically relative to an axis of the golf club shaft; and one or more layers of composite material wrapped around the coils of fiber and disposed radially outwardly of the coils of fiber.

A golf club shaft includes: a butt end; a tip end, where the golf club shaft is tapered between the butt end and the tip end; coils of fiber wound helically relative to an axis of the golf club shaft; and one or more layers of composite material wrapped around the coils of fiber and disposed radially outwardly of the coils of fiber.

A shaft includes a tip end and a butt end. In the shaft, a flexural rigidity at a point located 130 mm apart from the tip end is denoted by E1, a flexural rigidity at a point located 1030 mm apart from the tip end is denoted by E10, and a torsional rigidity at the point located 130 mm apart from the tip end is denoted by G1. A ratio (E10/E1) is greater than or equal to 2.4 and less than or equal to 8. The flexural rigidity E1 is less than or equal to 2.5 (kgf.Math.m.sup.2). The flexural rigidity E10 is greater than or equal to 6.0 (kgf.Math.m.sup.2). The torsional rigidity G1 is greater than or equal to 0.5 (kgf.Math.m.sup.2). A ratio (E1/G1) is greater than or equal to 1.0 and less than or equal to 4.0.

A shaft includes a tip end and a butt end. In the shaft, a flexural rigidity at a point located 130 mm apart from the tip end is denoted by E1, a flexural rigidity at a point located 1030 mm apart from the tip end is denoted by E10, and a torsional rigidity at the point located 130 mm apart from the tip end is denoted by G1. A ratio (E10/E1) is greater than or equal to 2.4 and less than or equal to 8. The flexural rigidity E1 is less than or equal to 2.5 (kgf.Math.m.sup.2). The flexural rigidity E10 is greater than or equal to 6.0 (kgf.Math.m.sup.2). The torsional rigidity G1 is greater than or equal to 0.5 (kgf.Math.m.sup.2). A ratio (E1/G1) is greater than or equal to 1.0 and less than or equal to 4.0.

A golf putter has a shaft of composite materials, a putter head having a stud for mounting to the shaft of composite materials, and a grip affixed to the shaft. The shaft is a hollow shaft and the surface is sanded and cleaned before a first layer of pre-preg material is rolled onto the shaft and secured with an adhesive layer. At least one additional layer of the pre-preg material is rolled onto the first layer of the pre-preg material and secured using adhesive. Additional layers of pre-preg material may be applied to the hollow shaft. Cellophane is wrapped on top of the at least one layer of the pre-preg material prior to heat curing of the hollow shaft. After heat curing, the cellophane is removed and the surface is sanded and decorated.

A golf putter has a shaft of composite materials, a putter head having a stud for mounting to the shaft of composite materials, and a grip affixed to the shaft. The shaft is a hollow shaft and the surface is sanded and cleaned before a first layer of pre-preg material is rolled onto the shaft and secured with an adhesive layer. At least one additional layer of the pre-preg material is rolled onto the first layer of the pre-preg material and secured using adhesive. Additional layers of pre-preg material may be applied to the hollow shaft. Cellophane is wrapped on top of the at least one layer of the pre-preg material prior to heat curing of the hollow shaft. After heat curing, the cellophane is removed and the surface is sanded and decorated.

An object of the present invention is to provide a novel fiber-reinforced epoxy resin material having improved strength. The fiber-reinforced epoxy resin material of the present invention comprises a cured product of an epoxy resin composition and a reinforcing fiber, wherein the epoxy resin composition comprises a novolac type epoxy resin as an epoxy resin component, and the cured product of the epoxy resin composition has a swelling ratio in a range from 20 mass % to 44 mass % in methyl ethyl ketone.

An object of the present invention is to provide a novel fiber-reinforced epoxy resin material having improved strength. The fiber-reinforced epoxy resin material of the present invention comprises a cured product of an epoxy resin composition and a reinforcing fiber, wherein the epoxy resin composition comprises a novolac type epoxy resin as an epoxy resin component, and the cured product of the epoxy resin composition has a swelling ratio in a range from 20 mass % to 44 mass % in methyl ethyl ketone.

Golf clubs with improved aerodynamic properties. In an example, a golf club has a golf club head; a grip; and a shaft having a tip end and a butt end. The golf club head is coupled to the shaft at the tip end, and the grip is coupled to the shaft at the butt end. An average bending stiffness of a butt end portion of the shaft is greater than 3.70 times an average bending stiffness of a tip end portion of the shaft.

Golf clubs with improved aerodynamic properties. In an example, a golf club has a golf club head; a grip; and a shaft having a tip end and a butt end. The golf club head is coupled to the shaft at the tip end, and the grip is coupled to the shaft at the butt end. An average bending stiffness of a butt end portion of the shaft is greater than 3.70 times an average bending stiffness of a tip end portion of the shaft.