Is cpm the unit that shaft stiffness is measured by

[radd]

Ive got a speeder 757 stiff in my driver its cpm is 280.id like a shaft that is slightly softer than the speeder 757 so if i got a cpm of say 275 would that be softer. I notice some x shafts are 275 while some s flexes are 280 285 does that mean the s is stiffer than the x. cheers

[haribo]

cpm (cycles per minute) is one way to measure the stiffness of a shaft. 10 cpm equals one full flex, let's say from s to x. With 280 cpm (depending on shaft length and swingweight) your driver seems to be extra (X, probably more) stiff. Going to 275 would make it half a flex softer.

Btw, I'm playing a 757 in s-flex in a GBB II 415. Don't actually know what it flexes out to but it feels right. Meaning I usualy have my drivers set to about 265 cpm at 44.5". The GBB II 415 is a bore-thru which makes a shaft play stiffer, that's why I went with a s-flex instead of a x. Don't know what driver (insertion depth) you are playing but 280 sounds like it got tipped to play a lot stiffer.

I'm sure more knowledgable people like Joe Kwok can tell you more.

haribo

[joey3108]

Haribo,

You pretty much got everything in the button.

I just have to add a bit here.

We need to know what is exactly your set up right now ( head , lenght and sw ) to be able to tell more.

Plus, Every CPM machine are not the same reading. The way i see it, CPM machine is good if you know what you got from that machine and they are only good to build a consistent set . After that is the knowledge of the Clubmaker about every each one of shafts carracter they carry.

Yes 280 is way up there. that is between X and XX.

Joe

[radd]

I got my reading from the fujikura website so obviously im wrong. my driver is a 510tp retail can you tell me roughly what will the cpm be

[DoubleAA]

cpm (cycles per minute) is one way to measure the stiffness of a shaft. 10 cpm equals one full flex, let's say from s to x. With 280 cpm (depending on shaft length and swingweight) your driver seems to be extra (X, probably more) stiff. Going to 275 would make it half a flex softer.

Btw, I'm playing a 757 in s-flex in a GBB II 415. Don't actually know what it flexes out to but it feels right. Meaning I usualy have my drivers set to about 265 cpm at 44.5". The GBB II 415 is a bore-thru which makes a shaft play stiffer, that's why I went with a s-flex instead of a x. Don't know what driver (insertion depth) you are playing but 280 sounds like it got tipped to play a lot stiffer.

I'm sure more knowledgable people like Joe Kwok can tell you more.

Thats what I have heard, the CPM's were much different for my 983K compared to my TM580.

haribo

[radd]

so if you increase swing weight does that decrease cpm ie make the shaft weaker.

[haribo]

Double,

Correct. Titleist drivers have a bore-thru of about 3.5". (TM blind bore's are only 1.5" to 1.75 inches!!!) 3.5 inches is so much it not only changes the flex drastically, it also changes the characteristics of a shaft. Fuji for instance has a 3 inch long protective sleeve build into the tipps of all their shafts. This alone gives you an idea how much the Titleist bore-thru can change a shaft. (and the reason why Fuji built that Titleist Speeder shaft.) Because of this most Pro's (Titleist does it too) turn it into a blind bore, by leaving a false tipp (cut-off tipp from an old shaft) at the bottom of the bore-thru. Makes it so much easier to keep the flex under control.

Radd,

The measurement you got from the fuji website is for an uncut, raw shaft. In order to find out what's it flexes to in a driver you got to get it measured again.

On a side note, I actually stopped looking for a "correct" cpm reading in a new driver. I go completely by feel now. Know pretty much what I want and how certain shafts react.

Also, as Joe said it doesn't mean too much. It is just an "orientation point". Bend point, torque, soft or stiff tipp ... all those things can give you a reading that looks right "on paper" but when you play the club it feels completely off.

Yes, increasing the swingweight makes a shaft play weaker.

The GBB II 415 I use has a relative light head weight. meaning I'm using some lead tape to increase swingweight. But I also don't want to go overboard to avoid making it too weak. On the other hand I do prefer heavier clubs. Well, to get both I do a little trick. I put also some lead tape just below the grip. This increases dead weight without decreasing swingweight. Plus it counterbalances the club nicely.

Hope this helps. haribo

[Eveleth]

A little information I received from the Fujikura Rep. Fujikura uses a 7.25 inch butt clamp with a 201 gram head weight in their CPM testing as opposed to a 5 inch butt clamp for most manufactures. The net result is their CPM rating would be 12-13 cycles higher becuse of this.

[joey3108]

I got my reading from the fujikura website so obviously im wrong. my driver is a 510tp retail can you tell me roughly what will the cpm be

Those are a measurement for raw lenght Cpm at 46" w/ 205 - 200 grams tip weight.

[Guest]

How does CPM convert into 5.5, 6.0, 6.5, etc. I'm assuming these two numbers essentially represent the same info?

Thanks!

[rkruff]

What do numbers like "5.5" and "6.5" mean? A12: A golf club at 43" would oscillate in a frequency analyzer at 255 CPM to be a 5.5 flex designation. A 43" club oscillating 265 CPM would be a 6.5 flex designation. If you drop the "2" in "255" and "265", the relationship becomes apparent. These numbers of 5.5 and 6.5, etc. are all based on a club at 43" and every shorter club of the same flex designation will have a CPM increase of 4.3 CPM per 1/2". Every longer club will have a decrease of 4.3 CPM per 1/2". For example, if a club at 43" were 265 CPM, a club of the same flex designation at 42-1/2" would be 269.3 CPM (265 + 4.3). A club at 44" of the same flex would be 256.4 CPM (265 - 8.6). All three clubs are 6.5

[Guest]

What do numbers like "5.5" and "6.5" mean? A12: A golf club at 43" would oscillate in a frequency analyzer at 255 CPM to be a 5.5 flex designation. A 43" club oscillating 265 CPM would be a 6.5 flex designation. If you drop the "2" in "255" and "265", the relationship becomes apparent. These numbers of 5.5 and 6.5, etc. are all based on a club at 43" and every shorter club of the same flex designation will have a CPM increase of 4.3 CPM per 1/2". Every longer club will have a decrease of 4.3 CPM per 1/2". For example, if a club at 43" were 265 CPM, a club of the same flex designation at 42-1/2" would be 269.3 CPM (265 + 4.3). A club at 44" of the same flex would be 256.4 CPM (265 - 8.6). All three clubs are 6.5

Got It. Thanks!

[dyno]

5.5, 6.5, etc are Rifle FCM numbers but they've come to be equated with shaft flex as it is more intuitive. They do use a 2.5" clamp so the freq numbers you get from your local clubmaker will probably differ by approx 17cpm as most use a 5" clamp. Fuji and Aldila use something in the 7" range.

Don't get too hung up on butt freq. The more you use a freq analyzer, the more you realize how difficult it is to interpret the numbers.....as alluded to by Master Joe. There are many 'std's' such as the 8.6cpm/inch and 10cpm between flexes but often they don't hold up to real world scrutiny. It's very dependent shaft to shaft, especially graphite.

I've got a log book with about 50 shafts that I've measured and recorded notes on. Every clubmaker should have such a book to help decipher the wild intracies of each shaft they install. JMO.