Adding tip weights only purpose is to increase the weight at the head end of the club, which increases the swing weight. It is 2 grams of weight per one swing weight point at the head end of the club. 4 grams at the butt end of the club. Lead tape placed on the head can be used instead of tip weights, but some do not like the look of lead tape on the clubhead. Tip weights hide the additional weight added. Adding weight to the tip of the shaft, up to 8 to 10 grams, will not move the center of gravity to any significant degree. We do not recommend more than 10 grams in the tip of the shaft. As far as a reference, Ralph Maltby’s original book “Golf Club Design, Fitting, Alteration and Repair” has swing weight charts and explanations on the cause and effect of adding weight to the different parts of the club. It was last printed in the 1990’s, but the charts and the fitting information is still applicable today.