Patent ID: 8414417

Claim:
A golf club shaft, comprising a section between a point 500 mm and a point 800 mm from a tip end of the shaft, wherein the flexural rigidity EI of the shaft monotonically increases in the section from the point 500 mm to the point 800 mm, wherein Δ1/Δ2 is at least about 1.8 provided that the rate of change of the flexural rigidity EI of the shaft in a first subsection between a point 500 mm and a point 600 mm from the tip end is denoted by Δ1, and the rate of change of the flexural rigidity EI of the shaft in a second subsection between a point 700 mm and a point 800 mm from the tip end is denoted by Δ2, wherein the flexural rigidity EI of the shaft at a point 750 mm from the tip end is at least about 4.1×10 6 kgf*mm 2 , and wherein the flexural rigidity EI of the shaft at a point 155 mm from the tip end is about 2.0×10 6 kgf*mm 2 to about 2.5×10 6 kgf*mm 2 , and wherein the flexural rigidity EI of the shaft at a point 200 mm to 250 mm from the tip end is lower than a flexural rigidity of any other portion of the shaft along the entire length of the shaft, and wherein the maximum value of the flexural rigidity EI of the shaft along the entire length of the shaft is most about 5.0×10 6 kgf*mm 2 .