Method of evaluating restitution characteristic of golf club, system for evaluating restitution characteristic, and golf club

A system for evaluating restitution characteristics of a golf club head, comprising:

• an input device which acquires a response signal of a striking face of the golf club head, the striking face vibrating by an imparted impact force thereto;
• an analysis unit which obtains a resonant frequency of the striking face from the acquired response signal;
• and
• a calculating unit which calculates a coefficient of restitution of the golf club head, the restitution being performed when a golf ball is struck by the striking face.

A golf club, in which a restitution characteristics of a golf club head has been evaluated by using a method, comprising:

• imparting an external impact force to a striking face of the golf club head at which a golf ball is hit to cause the striking face vibrating;
• acquiring a response signal of the striking face which vibrates by the imparted impact force thereto to obtain a resonant frequency of the striking face from the acquired response signal;
• and
• calculating a coefficient of restitution of the golf club head from the resonant frequency, the restitution being performed when a golf ball is struck by the striking face.