Measuring the Golf Shaft

Several years ago I learned the term EI from engineers in the business of designing shafts. The instrument most used was in the $10K+ range, therefore not affordable to most. Not even all shaft brands have these instruments. It took about 2 years to come up with the original affordable EI measuring design. This shaft review site shows measurements taken with the Fit2Score instrument.

After many years of use, I decided to redesign and improve the instrument. The improved version 7 of the Fit2Score EI shaft measuring instrument is now available. This animation show it cycling on a shaft.


The gauge was re-positioned to improve accuracy and repeat-ability on measurements. Positioning pins are incorporated into a manufactured weight. The new press and weight design have been in use now on a retrofitted instrument for several months. Most of the original instruments have been upgrade with these assemblies. The newly designed self centering shaft support maintains the radius of the earlier design while eliminating the guide to center the shaft. The shaft naturally ‘falls’ to the bottom of the curve making readings faster and repeatable.

A hoop strength measuring fixture has been designed. It centers the shaft under the press and uses the 11kg weight and .0001 gauge to measure hoop strength. The new driver database structure includes fields for 7 hoop strength readings along the length of the shaft. This pulls aside another veil of shaft understanding. Hoop strength will now be shown in the reviews here. 

The instrument is now available for $2200. Excel based spreadsheets are included for gathering and analyzing profiles of shafts. Owner have the option of subscribing the the historical knowledge base that is at the core of the reviews on this site. Contact if you are interested in this essential club making instrument.

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas