spring effect 2

    The compression and decompression (springing back) of the face of a metal wood upon impact with the ball is called the “spring-like effect” (or “trampoline effect”). Spring-like effect on a golf club face is limited by the USGA through its rule regarding Coefficient of Restitution or COR, a measurement of how much energy is lost or retained when ball and club collide.

    The USGA limits clubface COR to 0.83, meaning no more than 83 percent of energy may be transferred from the club to the ball at impact.

    Thomas Golf (www.thomasgolf.com) produces drivers with the maximum spring-like effect allowed under the rules.