Patent ID: 7758446

Claim:
A method of adjusting the flex of a golf club having a dynamically swung golf club shaft comprising a first end attached to a grip section and a second end attached to a club head; wherein the method comprises: (I) providing a hollow club head shaft having a tubular cross-section and having an elongated cavity extending from the grip section to the club head and an opening at a first end; (II) providing a rigid shaft insert; wherein the rigid shaft insert has and outer surface, a female threaded inner surface, a length of 12 to 24 inches, and a weight of less than 50 grams; (III) coating a compressible friction agent onto the outer surface of the rigid shaft insert wherein the compressible friction agent is a silicone adhesive; (IV) curing the compressible friction agent on the outer surface of the rigid shaft insert; (V) providing a male thread penetration adjuster; (VI) placing the rigid shaft insert into the elongated cavity via the opening at the first end from about 1 inch to about 10 inches; (VII) adjusting the placement of the rigid shaft insert by placing the male thread penetration adjuster into the inner surface of the rigid shaft insert to mate with the female threads; and (VIII) removing the male thread penetration adjuster after desired position is obtained.