| 摘要 |
<p>A set of golf clubs, each having a striking surface with a different angle of loft and a coefficiency of friction. The coefficient of friction gradually increases in accordance with a gradual decrease of the angle of loft and a gradual increase of the club length. Therefore, the longer the club is, the smaller the angle of loft of the club and the larger the coefficient of friction becomes. It is easy to provide a back spin on a ball even with a longer club.</p> |
