Wilson Tennis on Twitter: "Stiffness: How much the racket frame flexes on contact Less Stiff=More Control More Stiff=More Power We measure Stiffness using the Stiffness Index (SI) Test. The more the racket
Is This the Perfect Combination? | Racquet Quest
HEAD Microgel Radical Midplus Tennis Racket - Pre-Strung 27 Inch Adult Racquet | eBay
Melbourne, Australia, 2015, May 9: String bed stiffness of a Tennis tour player frame is measured on strings. The measurement is used to check the qua Stock Photo - Alamy