Golf club shaft and golf club using the same
View Patent ↗A golf club shaft extending from a tip end to a butt end and made of fiber reinforced resin, comprises a weight being in a range of from 30 to 55 g, a whole length LS between the tip end and the butt end, a center of gravity of the shaft located with a distance LG from the tip end, a ratio of the distance LG to the whole length LS being in a range of from 0.54 to 0.65, a butt end portion which has a length of 300 mm from the butt end toward the tip end, the butt end portion including fibers including a low elastic fiber having an elastic modulus in a range of from 5 to 20 t/mm 2 , and a high elastic fiber having an elastic modulus greater than 20 t/mm 2 and not more than 50 t/mm 2 .
1. A golf club shaft extending from a tip end to a butt end and made of fiber reinforced resin, comprising
a weight being in a range of from 30 to 55 g,
a whole length LS between the tip end and the butt end,
a center of gravity of the shaft located with a distance LG from the tip end,
a ratio of the distance LG to the whole length LS being in a range of from 0.54 to 0.65,
a butt end portion which has a length of 300 mm from the butt end toward the tip end,
the butt end portion including fibers including a low elastic fiber having an elastic modulus in a range of from 5 to 20 t/mm 2 , and a high elastic fiber having an elastic modulus greater than 20 t/mm 2 and not more than 50 t/mm 2 , and
said fibers in the butt end portion comprising, in weight, the low elastic fiber of from 20 to 30% and the high elastic fiber of from 80 to 70%.
2. The golf club shaft according to claim 1 , wherein
said fibers in the butt end portion include a bias fiber inclined at an angle with respect to an axial direction of the shaft, and
the bias fiber is contained from 15% to 25% in weight of whole fibers in the butt end portion.
3. The golf club shaft according to claim 1 or 2 , wherein
the shaft has a torque value being in a range of from 5.0 to 8.0 degrees, and
torsional stiffness GI at a position of 150 mm length from the butt end of the shaft is not more than 2.5 kgfm 2 .
4. The golf club shaft according to claim 1 or 2 , wherein
the ratio of the distance LG to the whole length LS is in a range of from 0.55 to 0.64.
5. The golf club shaft according to claim 1 or 2 , wherein
the ratio of the distance LG to the whole length LS is in a range of from 0.56 to 0.63.
6. The golf club shaft according to claim 1 or 2 , wherein
said fibers in the butt end portion comprise, in weight, the low elastic fiber of from 21 to 29% and the high elastic fiber of from 79 to 71%.
7. The golf club shaft according to claim 1 or 2 , wherein
said fibers in the butt end portion comprise, in weight, the low elastic fiber of from 22 to 28% and the high elastic fiber of from 78 to 72%.
8. The golf club shaft according to claim 3 , wherein
said torsional stiffness GI at a position of 150 mm length from the butt end of the shaft is in a range of from 1.0 to 2.3 kgfm 2 .
9. The golf club comprising a club shaft according to claim 1 or 2 , and a golf club head.