What is shaft stiffness measured in?

[StefanUrkel]

How do I know if a stiff flex may be stiffer than an extra stiff of another brand?

[JxQx]

The frequency in CPM (cycles per minute), along with the bend profile give you a pretty good idea of what the true stiffness is.

Edited October 5, 2016 by JxQx

[WUTiger]

3 hours ago, JxQx said:

The frequency in CPM (cycles per minute), along with the bend profile give you a pretty good idea of what the true stiffness is.

Miyazaki has probably the most complex bend profile: a code system that measures stiffness at four points along the shaft.

[IndianaDundee]

Shaft stiffness is measured in manhood points.  I have seen players that don't hit their driver 200 yards but insist they need a stiff shaft.  I have also seen a stock shaft labeled stiff that swings like an overcooked spaghetti noodle.  I think they used common core math to measure stiffness.

[MRugroden]

There are no standards among manufacturers for shaft designations.  Some attempts have been made to put everyone on the same page but the manufacturers claim proprietary techniques and information would be lost.  

[StefanUrkel]

So basically there is no inherent meaning of an X-Stiff,Stiff,regular. They are just arbitrary things? A stiff on one brand could be stiffer than an X-stiff on another?

[WUTiger]

On 10/5/2016 at 2:29 PM, JxQx said:

The frequency in CPM (cycles per minute), along with the bend profile give you a pretty good idea of what the true stiffness is.

This earlier reply (above) gets us started...

10 hours ago, StefanUrkel said:

So basically there is no inherent meaning of an X-Stiff,Stiff,regular. They are just arbitrary things? A stiff on one brand could be stiffer than an X-stiff on another?

There's no standard for flex, but you can compare shaft models by CPM vs. "stated" flex. In general the Dynamic Golds are a bit soft to stated flex (and heavier), the ProjectX are stiffer to stated flex, and the KBS (non-C taper) are "average". See chart embedded in spoiler for details.

Spoiler