Re: ShopTalk: MOI Matching

[Ed Reeder]

Mark, Wishon's formula has not been published.  They do two basic types of MOI matching. The first uses a database of primarily Wishon heads, grips, and shafts predict up front what shaft trimming and headweight changes are needed to produce a specific MOI.  There are a few non-Wishon shafts in the database.  You can trade off club length changes vs. headweight changes when build your "virtual club" to reach the target MOI.  When you have everything the way you want you have a "cut list" to build the set. The second uses the actual components of the club you are building.  You need to measure: length, balance point, total weight, period count, and location of where additional headweight would be added.  From this information it determines the amount of headweight that needs to be added or subtracted (as you can guess, subtracting weight is a bit of a problem) to reach the target MOI. The problem with the first method is that  the database is way out of date and doesn't include all of 2004's heads and shafts much less any of the new 2005 products.  You can fairly easily add your own heads and grips, but shafts are a problem as they measure a bunch of data on each shaft (I'm guessing every inch) to capture the unique weight distributions of different shafts. The problem with the second method is that you are only provided information for headweight changes.  If you need to reduce MOI you can also reduce the clublength, but you are left on your own to try and figure it out the length changes on your own.  Wishon says they can't provide generic club length instructions as they don't know the weight distribution for the particular shaft you are using. Having said all this, I am a strong believer in MOI matching.  I use Wishon's MOI product and have had great success with the sets I've built. /Ed [EMAIL PROTECTED] wrote: Dave, Thanks for replying, using 1/2" length increments, that would be: 6 iron- D1 7 iron- D1.5 8 iron- D2 9 iron- D2.5  ???? I'm real curious as to what the Wishon software model would bring back as suggested headweights to get an MOI match. Is the formula they use calculated or adjusted by actual experience? Or is final MOI matching only acheivable by a period counter and lead tape? Thanks, Mark