| 摘要 |
PROBLEM TO BE SOLVED: To provide a racket frame for a beginner capable of demonstrating excellent repulsion performance and surface stability in hitting a ball even while securing a large sweet spot area. SOLUTION: While the out-of plane primary natural bending frequency (F1) of a shaft-grip part 8 is set within the range of 1,500 Hz-2,000 Hz, the ratio (F1/F2) of the out-of-plane primary natural bending frequency (F1) to the out-of- plane primary natural bending frequency (F2) of a ball hitting part 4 is set within the range of 3.9-4.8. Also, the ratio (F2/F3) of the out-of-plane primary natural bending frequency (F2) of the ball hitting part 4 to the out-of-plane primary torsional frequency (F3) of the ball hitting part 4 is set within the range of 1.0-1.3. |
