How are driver CC's calculated?

[mark blanchard]

I just received a new Jetspeed driver and I was stunned by how big the head is. By far the biggest driver head I've ever seen, bigger than the SLDR or even than the massive G25, which looks deceptively large when viewed from above because it's a bit of a squashed flat egg. I pulled out all the drivers I currently have on hand and sure enough, the Jetspeed looks much bigger than anything. So I decided to measure myself.

I'm no physicist, but I remember my Archimedes and in about 2 minutes I constructed a nifty little volumetric overflow tank into which I could catch the run-off in a graduated beaker and roughly measure volume. Since a cubic centimeter = a milliliter, I was all set, confident I could get within about 5 cc's of actual head volume.

What I found was is a HUGE actual difference in clubs that are nominally "460". The Jetspeed was the biggest, measuring about 450 cc's, while the Optiforce 460 was about only 425 and the Nike Covert was only 380 cc thanks to its huge bottomside cavity. An older Cleveland XL270 measured in at 430, an old Taylormade r580 came in at 395 cc's and my antique Titleist 983K was about 360.

Am I measuring this wrong? Does the Nike's cavity count against it in some way or does Nike just not want us to know that their head only has a volume of 380 "under the hood". Since manufacturers all lie about their clubs loft and face angle spec's anyway (except for Mizuno), are they simply marketing most clubs as 460 because that's what we'll buy?

 

[blugold]

All companies lie? Is there proof that they are actively intentionally deceiving us?

 

[JRod]

I just received a new Jetspeed driver and I was stunned by how big the head is. By far the biggest driver head I've ever seen, bigger than the SLDR or even than the massive G25, which looks deceptively large when viewed from above because it's a bit of a squashed flat egg. I pulled out all the drivers I currently have on hand and sure enough, the Jetspeed looks much bigger than anything. So I decided to measure myself.

I'm no physicist, but I remember my Archimedes and in about 2 minutes I constructed a nifty little volumetric overflow tank into which I could catch the run-off in a graduated beaker and roughly measure volume. Since a cubic centimeter = a milliliter, I was all set, confident I could get within about 5 cc's of actual head volume.

What I found was is a HUGE actual difference in clubs that are nominally "460". The Jetspeed was the biggest, measuring about 450 cc's, while the Optiforce 460 was about only 425 and the Nike Covert was only 380 cc thanks to its huge bottomside cavity. An older Cleveland XL270 measured in at 430, an old Taylormade r580 came in at 395 cc's and my antique Titleist 983K was about 360.

Am I measuring this wrong? Does the Nike's cavity count against it in some way or does Nike just not want us to know that their head only has a volume of 380 "under the hood". Since manufacturers all lie about their clubs loft and face angle spec's anyway (except for Mizuno), are they simply marketing most clubs as 460 because that's what we'll buy?

Thank you this made me chuckle.

 

[JRod]

It's measured by the amount of water it displaces I believe.

 

[jlukes]

http://www.golfclub-technology.com/volume.html

 

[mark blanchard]

All companies lie? Is there proof that they are actively intentionally deceiving us?

With regards to the stated loft on drivers, many studies have been done that have measured true loft compared against stated loft. The one on mygolfspy found that of the major manufacturers only Mizuno came statistically close to what they stated. I believe that Adams is now making "tight tolerances" (what you get vs. what they state) a part of their 2014 marketing pitch, so they are recognizing the discrepancy. I've seen tour drivers for sale on Ebay that had their true measurements stated on a part of the labels that varied from stated by as much as .75 degree in loft and 2.0 degrees in face angle, so that's what I meant by "lying". Perhaps I should have said "guesstimating".

I understand that my volumetric measurements are not precise but they should not differ from the cap by soooo much. All manufacturers must stay under 460cc, but I just assumed that they would all hover just under the cap when they advertised a 460 head. The Cally Optiforce 460 was less than 440 and they make a 440 head!

 

[mark blanchard]

http://www.golfclub-technology.com/volume.html

Thanks for the link. That's exactly what I did and I also factored in some wiggle room of + or - 5-10 cc's. Only the Jetspeed came close to the limit and its head is MASSIVE. The others were way under. In my opinion, these differences cannot be accidental. If you take a balloon with 460cc's of water, it'll still be 460 no matter what shape you squish it into. CAD/CAM programs can do the same exercise when designing a driver head and their volumetric calculations are very precise. This means that if true head size is significantly different than the limit, they are doing so on purpose. Perhaps for aesthetic reasons, perhaps because they know that if they push the limit their heads will look enormous to the consumer, like my reaction to the Jetspeed. Nike had lots of wiggle room and could have made their head much larger, but because the walls of the cavity actually create more mass, perhaps they reached a swingweight/strength limit that meant their head could only be 380. I dunno, I was hoping someone else would.

Here's a pic of the Covert, Jetspeed, Cleveland XL270 and Optiforce 460 side by side.

 

[TeedUpThoughts]

It seems difficult to me to calculate such minute differences outside of a controlled lab, I vaguely remember high school chemistry lab and how small an mL was. I'm sure the tolerances are pretty close, and as you mentioned the variance on loft was .75 degrees max...that's not much when we are talking about amateur golfers. I appreciate your efforts, but have to believe that MOST drivers are close to the stated volume... why wouldn't they be?

 

[mark blanchard]

It seems difficult to me to calculate such minute differences outside of a controlled lab, I vaguely remember high school chemistry lab and how small an mL was. I'm sure the tolerances are pretty close, and as you mentioned the variance on loft was .75 degrees max...that's not much when we are talking about amateur golfers. I appreciate your efforts, but have to believe that MOST drivers are close to the stated volume... why wouldn't they be?

The volumetric differences are more than you think and are easily measured in the home. To put them in terms the layman can appreciate: 460 cc = 15.55 ounces, 380 cc = 12.85 ounces. If both were in 16 oz soda bottles you may not notice the short fill on the first, but you'd scream rip-off with the second.

Regarding mismarking of spec's, that's what I thought too ... until I started reading the articles which stated the reasons for their intentional mismarking. The manufacturers know that most average golfers should play higher lofted drivers, but our macho egos WANT to play low lofts like the pros. So the manufacturers fudge the markings downward so we will think we're gaming the big guns. If a Driver measures 9.75, the manufacturer will stamp a 9.0 on it, never a 10 or a 10.5.

Next, I contend that if true face angle and loft specs are off by as much as 2.0 degrees and .75 degrees respectively, and today's adjustment systems can only adjust by 1.5 degrees and 1.0 degree respectively, then it actually DOES make a difference where you start because you are limited to where you can end up. I typically have problems hitting off the shelf TMag drivers, because I just fade the crap out of them no matter how I adjust them and have to heel weight. Then my pro told me that stock TMag frequently measures 3.0 or more of open face, that's just the way they make them. I said, "What about this face angle dial on my R1?" He said it doesn't actually adjust anything and it's useless when you rest the driver on grass. So then I bought a tour issue RBZ2 with a measured open angle degree of only 1.75, and sure enough he was right, the problem disappeared.

 

[JB]

Ask the pro section guys.

 

[mark blanchard]

Ask the pro section guys.

Yeah, we know. Wouldn't it be nice if the pro's actually ever answered the original question!

 

[#Cookie]

Yeah, we know. Wouldn't it be nice if the pro's actually ever answered the original question!

You posted this 19 hours ago in the middle of peak holiday season.

Perhaps we allow them a bit more time?

 

[mark blanchard]

Yep and I've got a question from 3 weeks ago that is still unanswered. What's the harm if the peanut gallery chimes until they do? Or just get Smallville to erase it all since I have my answer now.

 

[JB]

Because it is the rules of the forum
For five years we have had a special section for those that wanted help from an expert in their field.
For those that want regular advice or assistance from THPers, we have over a dozen of other sections.
This will be changing in exactly 24 hours, but we see no harm in having this rule.