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=.alpha..multidot.X at its intermediate portion, where EI (Nm.sup.2) is the flexural rigidity, X (mm) is the distance from the tip end of the shaft, and .alpha. is a given constant. The .alpha. 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.
Each point obtained by plotting flexural rigidity EI measured at ten sites on a shaft is defined as from T(1) to T(10) in this order from the head side, and the formula representing a line K that passes the T(1) and the T(10) is [Y=aX+b1]. The values at the Y-intercepts on the lines that are parallel to the line K and that pass the points of from T(2) to T(9), respectively, are defined as from b2 to b9, respectively, and the minimum value among the values at the Y-intercept b2 to b9 is defined as bmin. In this shaft, slope "a" of the line K is 0.04 or greater and 0.06 or less; any one of the b3, b4, b5, b6, b7 and b8 is smaller than b1; and the bmin is any one of b4 to b7. The value (b1-bmin) is 24 (Nm.sup.2) or greater and 35 (Nm.sup.2) or less, and the value (b9-b1) is 0 or greater and 10 (Nm.sup.2) or less. This shaft achieves excellent flight distance performance and directionality of the hit ball.
A golf club comprises a club shaft having a tip end and a butt end, a club head being attached to the tip end of the club shaft, and a golf grip being attached to a region of the club shaft extending from the butt end toward the tip end of the club shaft, the grip having an end by the side of the butt end of the club shaft, wherein the club head has an moment (M) of inertia around a center line of the club shaft of not less than 6500 gcm.sup.2, and the club shaft has a bending stiffness (E) of not less than 5.0.times.10.sup.6 kgfmm.sup.2 at the position which separates 200 mm from the end of the grip toward the club head.
Points obtained by plotting flexural rigidity EI measured at ten sites on a shaft are defined as from T (1) to T (10) in this order from the head side, and the formula representing a line K that passes the T (1) and the T (10) is defined as [Y=aX+b1]. The values at the Y-intercepts on the lines that are parallel to the line K and that pass the points of from T (2) to T (9), respectively, are defined as from b2 to b9, respectively, and the minimum value among the values at the Y-intercepts b2 to b9 is defined as bmin. Slope "a" of the line K is 0.04 or greater and 0.06 or less; every one of the b3, b4, b5, b6, b7 and b8 is smaller than b1; and the bmin is any one of b4 to b7. The value (b1-bmin) is 30 (Nm.sup.2) or greater and 40 (Nm.sup.2) or less, and the value (b9-b1) is 4 (Nm.sup.2) or greater and 15 (Nm.sup.2) or less. This shaft either has a high-strength straight layer and a hoop layer, or has a textile layer.
