| 摘要 |
<p>A practice golf ball with a core and a cover has, upon initial measurement, a deflection BH1 (mm) when compressed under a final load of 1,275 N from an initial load of 98 N and an initial velocity BV1 (m/s), and also has, when measured again after being left to stand for 350 days following initial measurement, a deflection BH2 (mm) when compressed under a final load of 1,275 N from an initial load of 98 N and an initial velocity BV2 (m/s), such that the difference BH2−BH1 is not more than 0.2 mm and the difference BV2−BV1 is not more than 0.3 m/s. The ball has excellent durability to cracking and durability of appearance, and also maintains a stable feel and flight performance over a long period of time.</p> |
