Stiffness vs. CPM - misnomer or consistent?

[pdaero]

Hey guys,

 

so i wasn't sure as to where to post this after looking through many forums, but i am looking for the right stiffness. Apparently, i looked on this website that i found off of the top search of Google regarding my HTD CB-65 shaft at stiff that i tipped 1/4" and play at 44.75" at D2, and it said that it had a CPM of 282! i found that hard to believe, considering that the UST V2 75 stiff is at 267 and a somewhat stiff shaft. Anything would be wonderful!

 

Thanks,

PDaero

[Wormburner.]

Butt stiffness is only one part of constitutes the overall profile. The V2 may have a totally different bend point, and totally different tip, plus different reading all the way down the shaft.

[pdaero]

thanks alot. oh that brings another question - is butt stiffness the same as CPM or different? they seem to be similar numbers..

[Wormburner.]

most CPM numbers bandied about will be butt stiffness, but what clamp? what weight? who did it? blah blah blah, its a rough guide at best unless you trust the source

[pdaero]

I have no idea, and I don't know to trust the source or not. It just wouldn't make sense for my driver shaft (that plays for 100-110 mph) to play as stiff as what Matrix shafts consider their XX flex or UST considers their Proforce V2 X flex at 282 CPM. So I will end up not trusting it and go by mph for my next shafts.

[thewitt]

When someone says "CPM" and they are talking about a single number for the golf shaft, it's butt frequency - measured by clamping the butt in a frequency machine, hanging a weight on the tip and measuring the shaft.

 

It may be measured differently between manufacturers, but that's not the real problem.

 

The real problem is butt frequency does NOT represent stiffness independent of the model of the golf shaft.

 

Some shafts are butt soft and tip stiff, and some are butt stiff and tip soft. These may play the same from a flex perspective and yet the butt soft shaft may read 10-20 cpm lower in "butt frequency" and look like a much softer shaft from that perspective.

 

Check out some of the shaft profiles at shaftprofiles.com for examples.

 

-t

[3step]

Comparing or choosing shafts by butt stiffness, or CPMs, or using any measure of swing speed, lead you to the same place - "guessville".

 

It may be fun to put fingers to the keyboard for all the world to see, but it still leads you to a random selection.

 

Regards, 3