Shaft Flex Numbering

[terrygray]

I have seen golf clubs where the shaft flex is represented by a number instead of the usual letters L,A,R,S,X. For example, I've seen a Mizuno MSX Wide Body driver with a graphite shaft that has a flex of 9. I remember seeing another club listed with a flex of 2. Does anyone know what these numbers mean and how they relate to the more-common shaft flex designations of Ladies, Senior, Regular, Stiff and Extra- Stiff?

[Gary Hill]

"Flex" would be a relatively simple factor to fathom if club manufacturers followed a uniform set of standards.
Unfortunately, they do not. Flex standards vary not only from manufacturer to manufacturer but also, from model to model within certain manufacturers' product lines.

Zevo Shaft Flex's are represented by these numbers. 5=Ladies 6&7=Seniors 8=Regular 9&10=Stiff 11=X-Stiff.