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Author Topic: Are these symetrical?  (Read 3296 times)

Moon57

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Are these symetrical?
« on: March 10, 2007, 12:37:40 AM »
I have a Thing Lives, AU79, Zr40, Vendetta Black Solid. Are all these ball symmetrical? I looked on the Dyno website and couldn't find the words symmetrical or asymmetrical anywhere. Would be nice if all the ballmakers would state this in their ball descriptions. Thanks
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Dick
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Hogsharley

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Re: Are these symetrical?
« Reply #1 on: March 10, 2007, 08:47:03 AM »
http://www.bowlingballreviews.com/ball.asp?ballid=2460
http://www.bowlingballreviews.com/ball.asp?ballid=2299
http://www.bowlingballreviews.com/ball.asp?ballid=2814
http://www.bowlingballreviews.com/ball.asp?ballid=2017

They don't say here either. They all are 2 piece. They appear to have a flip block in them. I would say symmetrical with flip block in the AU79 and Zr40.
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Moose Nugget

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Re: Are these symetrical?
« Reply #2 on: March 10, 2007, 08:51:07 AM »
Yes they are symmetrical.  Only D/T offerings that are asymmetrical are their Centrifugal Mass and Threshold series'.
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Moon57

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Re: Are these symetrical?
« Reply #3 on: March 10, 2007, 10:21:23 AM »
Thanks for the replies. I kinda thought they were symmetrical, but it is curious it isn't mentioned anyplace.
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Dick
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charlest

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Re: Are these symetrical?
« Reply #4 on: March 10, 2007, 01:46:01 PM »
quote:
Thanks for the replies. I kinda thought they were symmetrical, but it is curious it isn't mentioned anyplace.
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Dick
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So many questions, so little time but I'm having fun.


Since 90%+ of new balls have symmetric cores, Manufacturers make a federal case when they make a ball with a mass bias (or preferred Spin axis").

FYI all asymmetric balls have a mass bias, but not all balls with a mass bias have an asymmetric core. "Asymmetry" refers to appearance or geometry. There are balls, like the One series which have a significant mass bias but they are symmetrical. They do it with pieces of the core having different densities.
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Moon57

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Re: Are these symetrical?
« Reply #5 on: March 10, 2007, 04:43:08 PM »
Charles, your right about asymmetry refering to appearance. I wasn't sure so I looked it up in the dictionary. So, basically symmetric cores with a mass bias are unbalanced weight wise but symmetric in appearance, yes? How does that differ dynamically from an asymmetric ball? Aren't they both accomplishing weight offset?

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Dick
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charlest

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Re: Are these symetrical?
« Reply #6 on: March 10, 2007, 05:08:58 PM »
quote:
Charles, your right about asymmetry refering to appearance. I wasn't sure so I looked it up in the dictionary. So, basically symmetric cores with a mass bias are unbalanced weight wise but symmetric in appearance, yes? How does that differ dynamically from an asymmetric ball? Aren't they both accomplishing weight offset?

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Dick
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So many questions, so little time but I'm having fun.


Dick,

The only difference is in the appearance, and that was my point. Because a core is symmetric does not mean it doesn't have a mass bias. So, to refer to mass bias balls as "asymmetric" is wrong and misleading. Theoretically, you could have an asymmetric core with no or very little mass bias. Actually, we have had some. The Brunswick Power Broove, the Columbia Scouts and the Roto-Grip Sonics (here's one: http://www.rotogrip.com/balls_ultra_sonic.aspx) all have noticeable amounts of asymmetry, but yet the manufacturers all have had a decided lack of comments about the balls having any mass bias at all.

I've been leading this campaign to NOT call something, cores with a mass bias, by the wrong name, "asymmetric" for a while now, and getting nowhere fast. I just thought I'd "preach" some more. Thanks for putting up with the "speech".

FYI Mo Pinel, a major proponent and designer of mass bias cores, has noted that balls with a mass bias differential of less than .008" might as well have nomass bias at all, because the effect of such core is minimal.

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shelley

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Re: Are these symetrical?
« Reply #7 on: March 10, 2007, 05:10:23 PM »
quote:
Aren't they both accomplishing weight offset?


It's the same thing.  Whether you add weight through density or core shape (or both like the Morpheus cores), you're still creating a preferred spin axis, which is what makes asyms/MB/PSA balls interesting.

SH
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Moon57

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Re: Are these symetrical?
« Reply #8 on: March 10, 2007, 05:21:37 PM »
Shelly "which is what makes asyms/MB/PSA balls interesting."

Couldn't that statement also include symmetric balls with a mass bias?



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Dick
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charlest

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Re: Are these symetrical?
« Reply #9 on: March 10, 2007, 07:30:44 PM »
quote:
Shelly "which is what makes asyms/MB/PSA balls interesting."

Couldn't that statement also include symmetric balls with a mass bias?

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Dick
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So many questions, so little time but I'm having fun.


I thought I had just said that???????
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Moon57

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Re: Are these symetrical?
« Reply #10 on: March 11, 2007, 08:16:04 AM »
Charles, The way I'm looking at this now the shape of the core doesn't mean anything at all. It's strictly about where weight is or isn't located in the ball.  Once the ball is thrown and becomes dynamic it's all about the weight locations.
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Dick
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shelley

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Re: Are these symetrical?
« Reply #11 on: March 11, 2007, 12:43:04 PM »
quote:
quote:
Shelly "which is what makes asyms/MB/PSA balls interesting."

Couldn't that statement also include symmetric balls with a mass bias?


I thought I had just said that???????


My statement was intended to cover balls with a PSA, no matter how they arrived at it.

SH
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