Patent ID: 7241230

Claim:
A hollow golf club head having a head volume of from 250 cc to 500 cc and comprising a club face portion for hitting a ball, a hollow portion disposed behind the club face portion, and a rib extending annularly through a crown portion, a sole portion and side portion, the rib provided on the inner surface of the head at a distance of from 1.0 to 7.0 mm from the inside of the club face portion, wherein a frequency F(fix) of a local minimum value of the first-order vibration mode in a frequency response function of the club head obtained by vibrating an input point on the club face and measuring the response at an output point on the club face is in a range of from 200 to 1400 Hz, a frequency F(free) of the smallest local minimum value of a frequency response function of the club head obtained by hitting the input point and measuring the response at the output point is in a range of from 5500 to 8000 Hz, and the ratio F(free)/F(fix) of the frequency F(free) to the frequency F(fix) is in a range of from 6.18 to 13.0.