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What Is CG?

SuperStroke
tpluff said:
Just curious, where's something like that come from? And how accurate is it.
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It came from Golf Spy I think. I did have the chance to talk to a Cobra sales rep at our club last week and he showed me the same chart on his iPad but said they couldn't publish it. I believe it's legit but corporate lawyers are very touchy about these things.
 
arydolphin said:
It will be gone soon enough because it's from the same site where I tried to link from and my post was deleted. But FWIW, I believe their research.
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Interesting. Not sure why it would go away, but ok.

tahoebum said:
It came from Golf Spy I think. I did have the chance to talk to a Cobra sales rep at our club last week and he showed me the same chart on his iPad but said they couldn't publish it. I believe it's legit but corporate lawyers are very touchy about these things.
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Oh ok. I can see why lawyers would be touchy about it. Seems to put a couple companies, based on my interpretation of the graph, in an area that's not very desired?
 
CG and MOI were some of those things I took up in pre-structural design calculus, back in college, not that I'm an authority on it. Goes to show college calculus had some use after all.
 
Waiting for the explanation as to why this is good. Doesn't seem like design wise it would be that hard to accomplish. What are the benefits? What type of player does it help?
 
I think it's that CG away from the AoA causes spin and doesn't maximize the forces you're applying to the club at the ball. For a driver, at least those that are triangular in section when cut across, the CG is around 1/3 the height of the triangle. Materials and weights move this CG around to match your AoA for the CG to come in line with the ball.

Short answer: longer drives, less effort.
 
arydolphin said:
It will be gone soon enough because it's from the same site where I tried to link from and my post was deleted. But FWIW, I believe their research.
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Its not any media research.
Its a slide from Cobra Golf R&D Power Point presentation that every major media member got to see, passed off as research.
Fupresti and myself sat through the same thing.

And ironically its an older one, rather than the current Cobra has that included 2016 drivers from TaylorMade. It was never meant for the public, and while we are leaving it up since it has no links (THP does not allow links to sites that do not honor embargo dates - most sites do), there is a reason almost every other major website did not publish it and its the same reason the cobra golf rep told TB that it was not for the public. Its an internal test conducted by their own team and depending on which company you visit, you will see something rather different.
 
Can't wait for the entire video to be put up. Is it fair to say like most clubs, the position of the CG will impact the performance of the club (not necessarily in a positive or negative way) allowing the club to be tuned to the players swing characteristics. I believe, but might be wrong, that all the drivers that allow you to move the weights around are impacting the CG to change the point the clubs rotate around and causing it to rotate faster or slower?
 
cnosil said:
Can't wait for the entire video to be put up. Is it fair to say like most clubs, the position of the CG will impact the performance of the club (not necessarily in a positive or negative way) allowing the club to be tuned to the players swing characteristics. I believe, but might be wrong, that all the drivers that allow you to move the weights around are impacting the CG to change the point the clubs rotate around and causing it to rotate faster or slower?
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That's why I decided to get the M1 because it is one of the few clubs that will allow me to fiddle with the CG, not only up and down, but back to front as well. The Callaway DBD is another one as well.
 
Researched this a little more today. There has to be a reason more companies are not lowering the cg. Seems like a pretty easy thing to do. Just adding some lead tape would certainly lower it. Assuming that graph is correct I should be able to calculate exactly how much mass needs to be added to the bottom of my XR to get the cg to center axis. Will report back soon on my findings.
 
OK so after listening to the video I have a question. He said that there is no such thing as zero center of gravity because in essence everything has a center of gravity at some point. So given that this has a center of gravity along the neutral axis line on the club where does that center of gravity land? more towards the front or more towards the back or is it in the middle of that center line along the neutral axis?
 
tahoebum said:
I like this graph showing CG and MOI. The King LTD is without peer now when it comes to low CG with high MOI. I guess we can have our cake and eat it too!

KINGLTD-CGNA.gif
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Thanks for the illustration. I for one enjoy this type of information. I also enjoy maltby and his measurements concerning cg location and moi in irons. While it's one person's measurement it's at least something to compare manufacturers.
 
sleuth said:
Thanks for the illustration. I for one enjoy this type of information. I also enjoy maltby and his measurements concerning cg location and moi in irons. While it's one person's measurement it's at least something to compare manufacturers.
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I hope that the real world performance of the LTD lives up to its CG and MOI numbers on this graph. Mine arrives with a HZRDUS Black shaft by Friday and I will report back this weekend on it's performance on the range and hopefully course. I own about 10 drivers that are less than 3 years old and this one excites me more than any of the others!
 
tahoebum said:
I hope that the real world performance of the LTD lives up to its CG and MOI numbers on this graph. Mine arrives with a HZRDUS Black shaft by Friday and I will report back this weekend on it's performance on the range and hopefully course. I own about 10 drivers that are less than 3 years old and this one excites me more than any of the others!
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One thing I find interesting is that there's a differences between the pro and non pro Ltd. I wouldn't think the difference being the face angle would impact the cg.

Wonder where the high heat competes on this chart.
 
tahoebum said:
I like this graph showing CG and MOI. The King LTD is without peer now when it comes to low CG with high MOI. I guess we can have our cake and eat it too!

KINGLTD-CGNA.gif
Click to expand...

This is pretty interesting stuff...I wonder how accurate it is. If low CG high MOI is what everyone is going for it sure paints some OEMs in a negative light and makes the LTD look super human.

That said, it makes it even more baffling why I launch the LTD driver identically to one of the other clubs on the chart that's nowhere near it. That's the problem with the internet sometimes...what to believe?
 
Maybe I'm missing some of the details, but from what I've been able to find online it sounds like the ideal CG position relative to the neutral axis depends on things like attack angle, launch angle, loft, etc. So the driver CG that works best for one person won't be best for another person with a different swing.
 
-CRW- said:
Maybe I'm missing some of the details, but from what I've been able to find online it sounds like the ideal CG position relative to the neutral axis depends on things like attack angle, launch angle, loft, etc. So the driver CG that works best for one person won't be best for another person with a different swing.
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Most or certainly many male amateurs spin it too much and/or launch it too low. Lower CG will help with both of those. The trick that Cobra has done maybe better than anyone, is make a very high MOI driver(forgiving) driver that launches higher while still keeping the spin down.
 
I really like listening to him. Explains it so we can all understand it.
 
Now I understand what they mean. Great video.
 
Schanker said:
Researched this a little more today. There has to be a reason more companies are not lowering the cg. Seems like a pretty easy thing to do. Just adding some lead tape would certainly lower it. Assuming that graph is correct I should be able to calculate exactly how much mass needs to be added to the bottom of my XR to get the cg to center axis. Will report back soon on my findings.
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Here's why it's hard to lower the CG. Here's the calc I did to lower the CG of the XR 3.3mm (which isn't very far).

The knowns:

-Head weight 200 grams
-Distance from center of club face to sole 30mm

Assume added weight is near the back of the club. This is approximately 25mm below center axis.

It would take 26.4 grams of weight to lower the CG only 3.3mm. That's about 13 sw points.
4e85f7252b53d3bb94cdb4a870c04342.jpg


So I guess I'll have to figure out how to replace the crown with carbon fiber, or just buy an XR pro.
 
Schanker said:
Here's why it's hard to lower the CG. Here's the calc I did to lower the CG of the XR 3.3mm (which isn't very far).

The knowns:

-Head weight 200 grams
-Distance from center of club face to sole 30mm

Assume added weight is near the back of the club. This is approximately 25mm below center axis.

It would take 26.4 grams of weight to lower the CG only 3.3mm. That's about 13 sw points.
4e85f7252b53d3bb94cdb4a870c04342.jpg


So I guess I'll have to figure out how to replace the crown with carbon fiber, or just buy an XR pro.
Click to expand...

It's been a long time for this kind of math for me, but I actually follow and understand it.
Thanks for providing and showing this.
 
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