US Patent 7367897 COR adjustment device

A golf club head with a variable coefficient of restitution is disclosed and claimed. The club head includes a bias member that contacts and exerts a force against the interior surface of the face. The force exerted against the interior of the face lessens the face flexibility, and decreases the club head coefficient of restitution. The bias member can be adjusted from outside the club head, allowing the manufacturer to precisely adjust the club head coefficient of restitution.