| 摘要 |
A tennis racket frame (10), including a sleeve composed of a fiber reinforced resin, having a weight not less than 180 g nor more than 270 g, when strings are not mounted in a ball-hitting face thereof surrounded with a head part thereof. Supposing that the strings are not mounted in the ball-hitting face, a secondary natural frequency (F1) of the racket frame in an in-plane direction thereof is set to not less than 200 Hz nor more than 320 Hz, a secondary natural frequency (F2) thereof in an out-of-plane direction thereof is set to not less than 480 Hz nor more than 650 Hz, and F1/F2 is set to not less than 0.3 nor more than 0.6.
|
