Cover strength and core strength

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markkuhn
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Cover strength and core strength

Post by markkuhn » May 17th, 2019, 4:43 pm

Folks, how much of a ball's shape and strength is dictated by its core or cover?
Is it a 50/50 split? Or does the cover effect motion more than the core?

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Re: Cover strength and core strength

Post by cw90stratos » May 17th, 2019, 4:53 pm

from what I know as a rookie. cover is bout 60% ish. core bout 30% ish. rest drilling.
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Re: Cover strength and core strength

Post by RobMautner » May 20th, 2019, 2:22 pm

75% Cover, 25% Core. Layout is part of the 25% that's core, as it is nothing more than how the core is positioned within the ball in relation to the bowlers grip. One of the most prevalent problems in modern bowling is that since the cover is easier to understand, it's O.K. to ignore the core. It's not!

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Re: Cover strength and core strength

Post by imagonman » May 20th, 2019, 7:19 pm

RobMautner wrote:75% Cover, 25% Core. Layout is part of the 25% that's core, as it is nothing more than how the core is positioned within the ball in relation to the bowlers grip. One of the most prevalent problems in modern bowling is that since the cover is easier to understand, it's O.K. to ignore the core. It's not!
NOT according to MO! { see 32:30 & 49mins}
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Re: Cover strength and core strength

Post by EricHartwell » May 20th, 2019, 10:06 pm

Mo's seminar is to teach drillers how to drill his ball designs.He doesn't put % numbers to gauge the relationship between cover and core as it pertains to ball motion. He basically says that the core/layout has the most influence.
I believe it is because there are too many variables that change these numbers. I'm also thinking that his new core designs are going to be "Radical", They are going to be really strong and will dominant the ball motion. The influence of the surface grit is going to be relegated to only controlling skid length.

I stated this in another post... viewtopic.php?f=6&p=111402#p111402" onclick="window.open(this.href);return false;
EricHartwell wrote: If you are going to keep the coverstock to be 60% of the ball motion core and layout need to be complimentary. Like strong core with a strong layout. If you go weak core and weak layout the coverstock is going to be more like 90% of the reaction. Go with a zero flare layout and you have a reaction that is 100% based on the cover.
I will go on to say a Strong core/layout with a weaker cover/prep, the cover will definitely be less than 50% of the reaction.
Again these are just generalities/estimations in an attempt to quantify the relationship between the cover/prep to core/layout. It changes based on many factors.

I believe it is possible to use too much surface and mask the layout.
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Re: Cover strength and core strength

Post by elgavachon » May 21st, 2019, 12:48 am

Personally, I don't think you can put numbers on it. It is the combination of the 2 which is important. You also have to figure weak covers seem stronger on dry lanes so you have covers which grab the dry hard (skid in oil) and covers with teeth that won't react much on dry conditions. It is the combination that makes the ball. For example: If you want back-end motion, use a weak core with a strong cover (strong on dry). There are core dominant balls and cover dominant balls. How would you say one size fits all and plug in numbers.

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Re: Cover strength and core strength

Post by b3y0nd3r » May 21st, 2019, 7:50 pm

40% layout, 30% core, 20% surface and 10% cover stock material. That's my take from my experiences.

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Re: Cover strength and core strength

Post by MegaMav » May 21st, 2019, 8:30 pm

Go with the ball motion study in the wiki from USBC.
Everyone has a different opinion based on their eye, what it wants to see and ball roll.
Data tells the truth.
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Re: Cover strength and core strength

Post by guruU2 » May 22nd, 2019, 1:15 am

Ever since the techno revolution in bowling that started in the mid 80s, I have heard or read of a wide range of numbers on this topic. Most of the numbers are unsupported with hard empirical data. The ball companies and the USBC have one studies. The USBC is public and provides a rigorous study on the topic and thus it is, at this time, the most definitive study we have. Thus I agree with MegaMav:
MegaMav wrote:Go with the ball motion study in the wiki from USBC.
Everyone has a different opinion based on their eye, what it wants to see and ball roll.
Data tells the truth.
Just remember, this is the definitive data and study we have at this point in time and thus it is open to revision. Thus, the only disagreement I have with the above quote is the last line. Data (facts) indicate that a truth statement can be possibly made but given further testing, the accepted "truth" is open to further revision.
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Re: Cover strength and core strength

Post by MegaMav » May 22nd, 2019, 6:22 am

guruU2 wrote:the accepted "truth" is open to further revision.
Spoken like a zen master. Thanks Gary. :ugeek:
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Re: Cover strength and core strength

Post by TomaHawk » May 22nd, 2019, 6:37 am

Is there a study, utilizing EARL or some other mechanical throwing device, in which the coverstock was changed on one particular ball and one ball only? I can't seem to find it.

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Re: Cover strength and core strength

Post by kajmk » May 22nd, 2019, 3:50 pm

MegaMav wrote:
Spoken like a zen master. Thanks Gary. :ugeek:
You may know that there are several books
"Zen and the art of ..."
As Casey Stengel said, "you can look it up"

I've often said that Gary should write a book.
If ever he does, we might add, "Zen and the art of bowling"
I have a Dalai Lama day calendar, every day has some of his words. Every now and then I see a little bit of Gary there ...

8-)

Other than the name of the group, there's no relevance, but the tune is a good one.

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Re: Cover strength and core strength

Post by snick » May 22nd, 2019, 9:10 pm

The faster the core/layout, the more aggressive the cover should be to accurately convert that energy to ball motion. When the core revs-up, the ball should move.
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Re: Cover strength and core strength

Post by Jochemke » June 14th, 2019, 2:14 pm

elgavachon wrote:Personally, I don't think you can put numbers on it. It is the combination of the 2 which is important. You also have to figure weak covers seem stronger on dry lanes so you have covers which grab the dry hard (skid in oil) and covers with teeth that won't react much on dry conditions. It is the combination that makes the ball. For example: If you want back-end motion, use a weak core with a strong cover (strong on dry). There are core dominant balls and cover dominant balls. How would you say one size fits all and plug in numbers.
How can you determine if a ball is core dominant or cover dominant? Are there any guidelines for this?

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Re: Cover strength and core strength

Post by elgavachon » June 15th, 2019, 8:31 am

Jochemke wrote:
How can you determine if a ball is core dominant or cover dominant? Are there any guidelines for this?
The diff. ratio gives the core strength. From the wiki glossary: Differential Ratio, or diff. ratio, is an indicator of the level of asymmetry of the core. The differential ratio is equal to the quotient of the Intermediate differential and the Total differential. Balls with higher diff ratios have a higher degree of asymmetry.
The diff. ratio is also an indicator of how quickly the ball will respond to friction. The higher the value, the faster the response to friction. This is the reason why Asymmetric cores tend to produce more angular break points than Symmetric cores. (Covers are a guarded secret according to Mo, so you would have to just go by what people are revealing).


Here is where he compared 2 of his Morich balls: viewtopic.php?t=740" onclick="window.open(this.href);return false; (see#2)

"The Awesome Hook is more core dominant with a weaker cover. Rolls up earlier and hooks less. Loses tilt and rotation sooner.

Then mania is more cover dominant. More total hook and continuation on the back end.

Thanks for asking the designer."

The question he was answering was: "How would you compare the reaction of the Mania to the Awesome Hook, in regards to shape and overall hook?

The numbers for both balls are below.

RG Diff. Asym. Diff. Spin Time Surface
Mania 2.486 .051" .013" 6.3 sec 1000 SIAAIR
Awesome Hook 2.498 .055" .028" 5.1 sec 500 Matte"

viewtopic.php?t=258" onclick="window.open(this.href);return false; (see #9)
"Core dominance vs. cover dominance, also, includes the strength of the coverstock. Here are my estimations: Diff. ratios > .25 are core dominant with weak covers. Diff. ratios > .35 are core dominant with weak to medium covers. Diff. ratios > .45 are core dominant with any covers, including "super" covers."


Another quote from Mo to reiterate: (see #8) viewtopic.php?t=207" onclick="window.open(this.href);return false;
"The 'Ntense is core dominant and the mania is cover dominant. Two different motions. Core dominant balls have more midlane with earlier forward roll. Cover dominant balls have more backend with continuation."

For symmetrical balls, I just use the total diff. as an indication of the core strength since most ball company's put smaller low flaring cores in balls they want to get down the lane easier. You still have to rely on the company to tell you how strong they consider the cover, though. I personally use the evaluations on each coverstock from Bowling This Month's ball reviews.

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Re: Cover strength and core strength

Post by kajmk » June 15th, 2019, 4:24 pm

Some valuable information Layed out by some knowledgeable caring folks.
Don't forget to thank them with a green + show of appreciation.

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Empathize

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