[LyleG]

The new Tom Wishon Tech notes are out and they have some great findings on MOI. MOI increases 37g-cm2 per gram of weight added to a club head. The cool part is that it doesnt really matter where the weight is added to have the same effect. Its takes just over 12g of weight to move the center of gravity in a driver head 1/8 of an inch, so as long as the weight is pretty evenly distributed it wont affect the clubs COG at all.

Here is the cool part.


Take a new callaway FT-1 driver, they have a MOI of roughly 5600. USGA max is 5900, but the USGA only measures raw heads. Now the Cally comes with a stock shaft weighing 65 grams and is 46 inches in length. So you pull that shaft and drop in a LIMEY weighing 55 grams, and trim it to 44 inches, being sure to tip trim it to allow for the added head weight. I would have to look up what corresponding wood would be the same weight as the Cally head when we are done with it. This will lower the swing weight roughly 13 full points. To get this back you need to add 26 grams of weight to the head. Using hotmelt or rat glue and a combo of lead tape you easily do this.
This will increase the MOI by 962g-cm2, meaning the new club will have a MOI of 6562.

An all day straight fairway finding machine, that get around the USGA MOI limit.