BallReviews
General Category => Drilling & Layouts => Topic started by: lefty50 on July 07, 2015, 06:38:18 PM
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current specs.. Left hand, 250 rev, 16.5 off the hand, high axis rotation.
the following is primarily, but not totally, a med-hvy oil and up scenario question.
Several years ago I was told by members on this forum whom I trust that with my style of bowling (low rev, high rotation), I would always want a low RG high differential ball. That did and still does make sense to me since my favorite ball at the time was a storm Special Agent. I've always done well with high diff symmetrical balls, which makes sense. Any ball with a high RG lopes down the lane too long and never gets into a roll. Low differential ball are pretty much the same.
It seems to me that these days the vast majority of balls are higher RG and lower differential, but yet they are advertised as big hook balls, which flies in the face of what my style encounters in real life. The answer is either that they are no longer making the type of ball I prefer (few exceptions) or that the cover stock is so dramatically different that I no longer have the low RG high differential qualification requirement.
I should add that I have had nothing but trouble with asymmetric and will only buy symmetric from now on. I know that there are few balls out there like the Motiv Covert Revolt, but there are many others I would like to try based on their rating to give me some help in the rev department, but I just can't see a .047 or so low rg ball revving enough for me.
Which is true?
Thanks in advance
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If .047" RG differential does not work for you, how high does it have to go for you to feel comfortable drilling one up?
(FYI #1 .060" is as high as one can legally go today.)
(FYI #2 the RG differential is a static measurement. Once drilled, the actual differential changes.)
(FYI #3 Once drilled, all symmetric cored balls become asymmetric.)
(FYI #4 Properly placed weight holes can change the RG differential and the intermediate differential to numbers that far exceed any static RG differential.)
I ask because the first symmetric cored strong ball I looked at has an RG of 2.49 and an RG differential of .052". (This ball is a 900G Respect)
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Focus first and foremost on cover strength then reference differential...RG is minuscule when you are talking thousands of an inch in dynamics
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Like Lefty50, I too fare best with symmetric balls ( weak asymmetric balls usually work for me, but not strong ones) that are high differential balls. The higher differential is more important to me than the RG. It wasn't always that way though as I once did best with lower RG - high differential balls, but learned with cover adjustments, I can make a higher RG ball work as long as the ball is a higher differential.
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I am more in the Ric camp. It seems to me when I bowl league that about 75% of the bowlers have the wrong surface prep on their equipment. Too many rely on OOB to be the end-all be-all for their game.
I think in reality you will want drilled dynamics to be on the strong side and adjust the cover prep for the length of oil you are encountering. During my wife's prep for the US Open, we changed the surface during the practice session until the ball rolled out then moved up from there.
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The mistake most bowlers incur is improper amount of surface - either way too much or too little and too strong of a layout (too much flare - over flaring) thus creating improper ball motion and angles...
Great post spmcgivern...
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Thanks for the replies, but we're going in the wrong direction from the original question... I know all the mantras, truisms, all balls are asymmetric, Rgs can be jacked around...yes, yes, yes... Apologies if I wasn't clear as to intent of the question. Let me rephrase the question to a scenario we've all heard before...
Question is really if today's coverstocks will allow a low rev player to ignore the natural tendency of a higher Rg ball, which will not rev as easily, to be considered a viable prospect for those of us who need the extra help to compete on slicker conditions. Let's go to our friend the snow tire... A fast revving snow tire will not push a car through ice if it cannot grip. Add studs, and it will begin to push thru even with a slower revving tire. Add more studs or longer studs, and it will push thru even better. This would create a condition where even a slow spinning tire could push thru the snow better than a quickly spinning one.
3-4 years ago, you would rarely see a heavy oiler with higher Rg and lower differential because you still needed the faster revving engine. If your hand didn't provide the revs, the core had to help. Higher diff provides higher potential... During those times, you would not see balls at .040 or lower diff claiming to be an oiler. Today, there are quite a few more balls claiming to push thru snow with slow revving engines... Heck, we even see UNHEARD of diffs that begin at .02x and .03x claiming to have a backend on medium to heavy conditions. Surface prep is important, but only a part of the answer, and 3-4 years ago surface wouldn't fix the problem, therefore the balls and the claims weren't being made. Why now? Are the coverstocks that much better?
Thanks
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My point is you are keying in on an insignificant number value by believing a small amount is effecting how quickly or slowly the ball revs (in your terms)...
How the ball slows down and transitions from skid to hook to roll is primarily defendant on how and where it slows down...
I'm not sure this is answering your question the way you're looking for but this is how I see ball reaction and/or motion...the surface is the primary enhancer then the amount of flare is allowed to effect...and the way I perceive flare management (layout) is predicated by the individuals rev rate
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Surface finishes today compared to a several years ago is the biggest difference.
The difference between a diff of .030 and .040 is .01 which is measured in the hundredths… .and yes can greatly increase just from drilling.
Things that hurt bowlers most are putting drill sheets in the box and posting core information. What the manufactures intent for the ball already factors in the core, cover ect. The goal is to match that with the bowler and the condition they are going to be bowling on.
A ball with a diff of .030 retains energy and even in heavier oil with the right surface can create downlane motion. No matter the core specs it's the surface along with the layout that you want to focus on when matching up to the conditions.
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Question is really if today's coverstocks will allow a low rev player to ignore the natural tendency of a higher Rg ball, which will not rev as easily, to be considered a viable prospect for those of us who need the extra help to compete on slicker conditions.
I think the answer you are looking for is YES.
When drilling a ball for a particular condition and for a particular bowler, all aspects of the ball are usually considered to determine said drill. Safe to say, the cover has the greatest affect to the overall ball motion. After that, let's assume the post-drilling ball dynamics is second. Beyond that we will assume is trivial for this exercise.
Whether the ball is high Rg or low Rg may affect the chosen drilling pattern. Whether the ball is high diff or low diff will also affect the chosen drilling pattern. Once drilled, the bowler would then go to the lanes and test the ball to see if the goal is met. If not, there are changes that can be made to meet said goal. You can change the surface (temporary) or you can add an extra hole to change the dynamics of the ball (permanent).
Because of changing conditions and variations in bowler consistency, cover changes are preferred as a first resort. So when the shot changes or when the bowler changes, you can change the cover and be successful. As a last resort, an extra hole can be added to change the dynamics of the ball and can be combined with any cover changes to achieve your goal. Only difference is the extra hole is permanent.
I think you are trying to conceive of a way to have a ball's core (before drilling) be the main deciding factor when in theory, the pre-drilled core is irrelevant.
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I appreciate all the expertise, but frankly, I side with those on the board who have all said frequently that although it may not seem to matter, it clearly does when we see the evidence of our own eyes. Evidence must be examined, not thrown aside, and I've seen Rg matter too often to deny my own experience.
Oh good grief, I give up. Why do I even post here... ? Sigh...
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5 Star thread ! ! ! BR gold.
Kidlost nailed it when he stated:
A ball with a diff of .030 retains energy and even in heavier oil with the right surface can create downlane motion. No matter the core specs it's the surface along with the layout that you want to focus on when matching up to the conditions.
My 900 Global Breakdown is a prime example of this.
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For me it's both, surface and Rg that have the biggest effect on ball motion.
I have several balls that are in the higher Rg range. They all have different cores and coverstocks. I have a high-speed-to rev release. All of these balls tend to go way too long when compared to my lower Rg balls. For this reason, I fare better using low Rg
equipment and simply adjust the surfaces when necessary.
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I guess in future posts you should merely ask your question then post all appropriate, acceptable responses you want to hear...that'll make it much easier on all us uneducated posters
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5 Star thread ! ! ! BR gold.
Kidlost nailed it when he stated:
A ball with a diff of .030 retains energy and even in heavier oil with the right surface can create downlane motion. No matter the core specs it's the surface along with the layout that you want to focus on when matching up to the conditions.
My 900 Global Breakdown is a prime example of this.
For me it has been the Ringer line, and the LT48. Wow very unexpected results. My ball choices are usually only limited by color, and terrible logos....the rest Im not worried about.
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I appreciate all the expertise, but frankly, I side with those on the board who have all said frequently that although it may not seem to matter, it clearly does when we see the evidence of our own eyes. Evidence must be examined, not thrown aside, and I've seen Rg matter too often to deny my own experience.
Oh good grief, I give up. Why do I even post here... ? Sigh...
So let me get this straight. You post a question based on your preconceived notions and then get upset when all of the answers aren't what you wanted to hear?
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As a lefty with somewhat similar stats, I think I understand lefty50's frustration. I too feel that as a high rotation/low rev lefty that I have a high sensitivity to higher RG's and lower Diffs. However I do not have an aversion to using asymmetric balls on heavier patterns.
lefty50, have you tried different layouts on asymmetric balls? Why are asymmetric balls out of the question?
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I guess I can't leave well enough alone....
lefty50, am I understanding it right that your experience has shown you that the difference between a low Rg core ball and a high Rg ball (pre-drilled) is noticeable to you?
Because I find it hard to believe it is the pre-drilled Rg that is the deciding factor in what you see. If we look at Storm as an example, the difference between their lowest Rg and highest Rg core is (2.58-2.48) or 0.1 inches. Motiv is 2.59-2.46=0.13. Brunswick is 2.578-2.487=0.091.
Also, it is almost universal across all brands that high Rg cored balls are in the lighter oil parts of the line-up while lower Rg cored balls are in the heavier oil parts of the line-up. Usually matched up with weaker coverstocks. Perhaps part of what you are seeing is more related to coverstock differences than pre-drilled Rg differences.
Also, it is almost universal across all brands that high Rg cored balls have smaller differentials than low Rg cored balls. Perhaps you are seeing a difference in differential instead of pre-drilled Rg differences.
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Here are two balls with the same cover, same differential, same cover prep, and same layout; only difference being the Rg, definitely go through the back part of the lane and through the pins differently for me.
http://stormbowling.com/products/balls/skyrocket
http://stormbowling.com/products/balls/hyroadpearl
Same can be said for these two balls as well. I never could get the Hyroad to roll as good as what everyone else did and frankly was very frustrating for me to watch everyone and their brother throw this ball and it look so great when I had dart or dive with it except for rare occasions, but that "subtle change" to the core Rg has made it near impossible for me to put down the Rocket, and give me a ball that I throw a lot.
http://stormbowling.com/products/balls/rocket
http://stormbowling.com/products/balls/hy-road
No extra holes used that would reshape the cores.
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tommygn,
I wonder how much core shape along with axis migration plays in what you are seeing.
Also, I personally feel that even though they both have R2S pearl, Storm has changed the formula over the years to match the current state of oils. R2S has been the Thunder line coverstock for a while and I think they change the formula ever so slightly to keep it relevant.
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It has to do with physics and moment of inertia. A higher Rg has a greater distance of the mass to the rotating axis thus a slower spin time, compared to more center heavy mass, which has a shorter distance from mass to the rotating axis.
A Higher Rg will spin slower with same torque applied compared to a lower Rg.
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What exactly is the difference in the RG
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What exactly is the difference in the RG
.03, which apparently is enough of a difference to allow me to miss in and either strike or leave something make - able, compared to missing in and leaving a 3-7-9 because the ball comes in behind the head pin too much.
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It has to do with physics and moment of inertia. A higher Rg has a greater distance of the mass to the rotating axis thus a slower spin time, compared to more center heavy mass, which has a shorter distance from mass to the rotating axis.
A Higher Rg will spin slower with same torque applied compared to a lower Rg.
I understand the physics of it, but those theories are based on the moment of release. Once friction is encountered then Rg should become less of a factor up until the ball rolls out. At that time Rg is meaningless.
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Sorry I can dispute your case as easily as you can defend it
Unless it the exact same bowling ball with a core differing by .03 in RG too many variables
And trust me I understand MOI as well as coefficient of restitution which is an effect also
If you feel 3/100,000 of inch matters great...I don't
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3/100 of an inch
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Thank you miss comma
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Here are two balls with the same cover, same differential, same cover prep, and same layout; only difference being the Rg, definitely go through the back part of the lane and through the pins differently for me.
http://stormbowling.com/products/balls/skyrocket
http://stormbowling.com/products/balls/hyroadpearl
Same can be said for these two balls as well. I never could get the Hyroad to roll as good as what everyone else did and frankly was very frustrating for me to watch everyone and their brother throw this ball and it look so great when I had dart or dive with it except for rare occasions, but that "subtle change" to the core Rg has made it near impossible for me to put down the Rocket, and give me a ball that I throw a lot.
http://stormbowling.com/products/balls/rocket
http://stormbowling.com/products/balls/hy-road
No extra holes used that would reshape the cores.
The obvious, and biggest flaw is that these are not the same balls with just the RG being different. Core shapes and densities make a difference as the ending ball after being drilled will have different specs.
You need to compare the exact same ball and core with only the low RG being different.
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Thank you miss comma
your welcome
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Here are two balls with the same cover, same differential, same cover prep, and same layout; only difference being the Rg, definitely go through the back part of the lane and through the pins differently for me.
http://stormbowling.com/products/balls/skyrocket
http://stormbowling.com/products/balls/hyroadpearl
Same can be said for these two balls as well. I never could get the Hyroad to roll as good as what everyone else did and frankly was very frustrating for me to watch everyone and their brother throw this ball and it look so great when I had dart or dive with it except for rare occasions, but that "subtle change" to the core Rg has made it near impossible for me to put down the Rocket, and give me a ball that I throw a lot.
http://stormbowling.com/products/balls/rocket
http://stormbowling.com/products/balls/hy-road
No extra holes used that would reshape the cores.
The obvious, and biggest flaw is that these are not the same balls with just the RG being different. Core shapes and densities make a difference as the ending ball after being drilled will have different specs.
You need to compare the exact same ball and core with only the low RG being different.
Oh really? ??? Then please explain to me how you change the radius of gyration of an object, without altering the object in any way.
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Sorry I can dispute your case as easily as you can defend it
Unless it the exact same bowling ball with a core differing by .03 in RG too many variables
And trust me I understand MOI as well as coefficient of restitution which is an effect also
If you feel 3/100,000 of inch matters great...I don't
I'm not disputing what is the primary factor in ball motion(cover stock material and it's preparation). I'm disputing the relevance of Rg as it pertains to being a factor of any kind, which is the way I took your response to the original post. Let me ask you, at what point does a ring 10 or ring 7 pin become a strike? Is it the difference of 1/32" (0.032), or 1/16" (0.062) at contact of the pins? How much force does the 6 or 4 pin have to exert on the 10 or 7 pin respectively to make that pin fall? What is the degree difference of Tommy Jones being able to roll the 2 pin in a 2-10, when many other players seem to leave it, a few thousands of an inch?
When a customer walks into my shop, clearly we need to get the right cover stock and cover preparation for their game in their hands based on the conditions and type of oil they are bowling on. But along with that, is picking an appropriate core as well, and for certain bowlers, the Rg can be just as important of a factor in carrying the 10 or 7 pin, or not leaving a 2-10 or 3-7, and leaving a make-able spare, as differential is, once you have the cover and cover prep narrowed down, on a missed shot.
And I agree with you, there are far too many possible variables when it comes to bowling. Especial how different bowlers will throw a ball, to delve into the realm of absolutes, like Rg doesn't matter. That's just my opinion.
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New cult has been born.. Rgnomaddah now.. That's a good one :)
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covermaddah
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covermaddah
......... indeeditdoesalotmorethanpeoplethink ^^^^^^^^^^^ ;)
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So your true belief is that 3/1,000 of an inch effects the motion & moment of inertia in an object of 8.5" in diameter?
You case study is flawed plus it is a limited instance
You cannot base any fact unless it is a controlled test...
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You are comparing similarities not absolutes
It's flawed
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You are comparing similarities not absolutes
It's flawed
Please answer the question, how do you change Rg of an exact core, without creating another different variable? Density= variable, shape= variable, layout=variable, total ball weight= variable.
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Generally it's density
So you've increased overalls as 3/1,000"'
You seemed quite fixated on such an insignificant number
Unless you take two IDENTICAL masses - one being 3/1,000" higher RG and NOTHING else, laid out and thrown side by side can you stare anywhere close to what you are attempting to state
You CANNOT base off an individual visual perception such as look how it goes through the pins
That's coefficient of restitution which deals more with surface that anything else
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Density is a changed variable, thus not the exact same. Still waiting.
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Still waiting for what? Your so called test is flawed...
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https://www.youtube.com/watch?v=9e9ysnJA9qA
Rg does matter... You may want a physics lesson :)
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I'm quite well versed in physics thank you
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I'm quite well versed in physics thank you
No way! Who would have thought? I thought you were just a poser in the bowling industry for the past 30 + years.
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Many on here would lead you to think that huh...
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Ric, I wasn't referring to you ! lol, you and I are on the same side!
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Thank you
I never know who is on who's side...
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If you are going to argue that my example is a "flawed" experiment noting that the core shapes are only similar in numbers but ultimately different, then you are saying that core shape matters in the equation. If core shape matters in any factor of the equation, given your argument with me, we measure the core relation after construction of the ball with the x y and z axis and the differences of them, and show that in Rg and differential (and sometimes intermediate differential) to quantify the core with numbers. The thing is, I can look at a core shape and get a rough idea of it's characteristics based on symmetry and comparing to previously released balls with similar characteristics, but what I CAN'T see, is the density of that said core, or see what materials were used to construct the core. I can't see how dense a flip block is, I can't see how dense the main body of the core is compared to the flip blocks, or be able to tell how much it weighs by looking at it. The weight of the core will also determine the amount and density of filler material needed to create a desired weight of a ball. Rg helps give us an idea of the core being very center heavy or being cover heavy. So, since my test is "flawed" because of it using two different cored balls, and Rg is one of the telling factors of the density of core to filler material to cover weight of a ball, then Rg matters, because it shows the numerical differences of different cores.
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A few years ago, the USBC did an intensive study into the factors affecting ball motion. They concluded that the 3 biggest factors were in order: coefficient of friction,
ball oil absorption rate and Rg. Core differentials, although a factor, were determined to be not as much an influence as the first three.
Although I tend to agree in general with this study based on my own experiences, I
disagree with Rg alone, as being a determining factor. Instead, I believe that a ball's "moment of inertia" to be a more deciding factor than Rg . It's that quantity that determines a ball's ability to "rev up" (or, in keeping with the physics, the ball's
ability to resist angular acceleration). Rg alone is simply a measurement of the distance of a center of (rotating) mass from an axis. If the mass increases but the distance remains the same, you increase the moment of inertia, making the ball harder to "rev-up" and vice versa. Rg is one component but it is not the only one.
If the mass remains the same, but its distance from its axis changes, then the ball's moment of inertia will change affecting the ball's ability to rotate. The mass value
needs to be known as well.
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Interesting you brought up the ball motion study, bergman. Always makes for a good read:
http://www.bowl.com/uploadedFiles/Equip_and_Specs/Equip_and_Specs_Home/08ballmotionstudy.pdf
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Waste of a million dollars
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Lefty50, I'm throwing this out there but I'm sure you already understand and know, but take any ball.... For example, a ball that's 2.55 high rg, 2.50 low rg which gives it a .050 differential.... Now, by putting the pin on your axis that's the ball's low rg and the more you raise it to 6 3/4" from your PaP it would be 2.55...
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The point I'm making is that you can take any ball and drill it to make it work :)
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All I know is he has a horse in his backyard that is extremely beat...yet still dead
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Brad don't bring that logic to a forum
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All I know is he has a horse in his backyard that is extremely beat...yet still dead
No pond I bet
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Ric and Kid -- lol ;)
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The point I'm making is that you can take any ball and drill it to make it work :)
Lefty50, I'm throwing this out there but I'm sure you already understand and know, but take any ball.... For example, a ball that's 2.55 high rg, 2.50 low rg which gives it a .050 differential.... Now, by putting the pin on your axis that's the ball's low rg and the more you raise it to 6 3/4" from your PaP it would be 2.55...
Maybe you can kind of get lucky with that working on over walled house conditions that are set up for as many styles and rev rates to still be able to score, but on competitive patterns, it isn't that simple. If it were that simple across the board, I highly doubt ball companies would spend the kind of money they do on R&D of core shapes and densities of said cores.
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All I know is he has a horse in his backyard that is extremely beat...yet still dead
So if someone doesn't agree with you, they are beating a dead horse? Got it.
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I just came back and was amused to see this thread still alive. I haven't read thru it and don't intend to, but I did read the last few... Ric, you just never shut up, do you? Your arrogance is fascinating, but boring. My whole point was that despite what numbers say, I cannot deny what my eyes see. The next logical step in the process is to research why. Hence, the question. I should have known better. that's why myself and others just don't come here any more... Previous studies can be a waste of money, but Ric's right... God man, get over yourself.
(Shaking his head, he departs again).
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I'm not sure how you're not employed in the industry somehow with your vast knowledge and input....I'm arrogant wow
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Actually, you have it backwards. You are the one saying "gospel", that Rg doesn't, and can't possibly matter to any style of player, or any miss in release. I'm saying that you can't make an absolute statement like that, because there are so many variables and so many different styles of players. If everyone threw the ball the exact same way, than you could argue that. The fact that you bring up variables one time, but ignore them at another time, is inconsistent.
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Again, 3/100 of an inch at the pins can be the difference of a strike and a single pin. Agree or disagree, Ric?
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I'm saying there are many other factors that come in to play that are much more important but then again I don't know s**t from what you and lefty think so not sure why anyone wastes their time...he even stated if he doesn't get the answer he wants everyone else is wrong...
In the biggest scheme of things no I would not sit back and consider 3/1000" in effecting a strike as I can adjust the surface and flare...
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That wasn't my question. At the pin deck, when the ball makes contact with the pins, can 3/100 of an inch, or a 1/32, be the difference of a strike or a a single pin? I'm not saying anything about the ball itself other than where it makes contact with the pins.
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The other issue is, you are relying completely on a factor that has had testing done, that shows to change within as little as 8 shots or less. The surface of the ball is only the surface you apply to it for a short time. The abralon pads we use are only consistent for a short time. Variables that you are conveniently ignoring. Surface of the ball changes, the core specs once drilled, do not.
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Surface of the ball changes to the lane. It levels out from original fresh surface to a different surface based on the lane. So if the ball is at 1000 grit and thrown on a newer smoother surface the track will smooth out to a higher number say around 3000 or so over a three game period. It will not continuous change after there much if used on the same surface. Now if the next day you go Bowl on some old wood lanes you would likely see the surface go back rougher.
3/1000 at the pin deck doesn't matter. If you think that's the reason your ball is leaving flat or ringing 10s then you have no hope.
If you think it matters go measure the lanes for their tolerances and see the differences from lane to lane. Then you can blame it instead of the rg, diff, int diff, barometric pressure, day of the week, time of year, or anything else that you believe matters. Bowling is hard enough without factoring in mental capacity.
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3/1000 at the pin deck doesn't matter. If you think that's the reason your ball is leaving flat or ringing 10s then you have no hope.
LOL!!
Oh yeah, just a little FYI, but 1/32" is .032, or 3/100 of an inch. Just thought I would finally clear that up for you. 3/1000 of an inch is .003.
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That box of popcorn didn't last long. Better go get another.
3835
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You can get popcorn but I'm getting lunch….. Hope they don't short me 3/1000" on my drink
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Ok now that's funny
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I just want to make sure I understand what all the hubbub is about. Is this conversation trying to decide how much, if any, the Low Rg of an undrilled ball matters? Or specifically in this case, a difference of 0.003" between two different balls with different core properties?
I am curious how many people know what the change is in the drilled low Rg compared to the undrilled low Rg of the same ball? How much can the drilled affect this difference with layout and balance hole location?
Some studies go into the overall effects of different drilling patterns along with balance hole location and then show what the final low Rg, differential and intermediate differential are. One example showed how different drillings and balance hole locations had variations of final low Rgs with a difference of 0.017" and everything in between. So for example, if a bowling ball had an undrilled low Rg of 2.488", the final low Rg, depending on layout etc., ranged anywhere from 2.487" to 2.504".
So based on this, why do I care if the difference between two balls is only 0.003" when I can drill the ball to make that difference up in a small change in some component of the drilling?
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I think the doctor shorted me 3/1000 of something when I was born...at least that is what the wife claims must have happened.
3835
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I just want to make sure I understand what all the hubbub is about. Is this conversation trying to decide how much, if any, the Low Rg of an undrilled ball matters? Or specifically in this case, a difference of 0.003" between two different balls with different core properties?
I am curious how many people know what the change is in the drilled low Rg compared to the undrilled low Rg of the same ball? How much can the drilled affect this difference with layout and balance hole location?
Some studies go into the overall effects of different drilling patterns along with balance hole location and then show what the final low Rg, differential and intermediate differential are. One example showed how different drillings and balance hole locations had variations of final low Rgs with a difference of 0.017" and everything in between. So for example, if a bowling ball had an undrilled low Rg of 2.488", the final low Rg, depending on layout etc., ranged anywhere from 2.487" to 2.504".
So based on this, why do I care if the difference between two balls is only 0.003" when I can drill the ball to make that difference up in a small change in some component of the drilling?
This conversion started out talking about the difference of the Rocket and the HyRoad, both in 15lbs. Rocket has an Rg of 2.54, and the HyRoad has an Rg, of 2.57 both with the same differential. The difference is .03, or 3/100 of an inch, or 1/32. Storm tries to design their bowling balls, so as after drilling, they don't change the core dynamics as much as what other shapes can do. I merely stated that with a Rocket and a Hyroad, both drilled the same layout, no extra hole, no IT thumbs, so very little manipulation of the core, that I see the Rocket shaping up a bit sooner, and gives me better angle through the pins, as to not 2-8-10 like I have with the Hyroad when getting it in the oil. The HyRoad is also a new one, not a 6 year old ball.
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The HyRoad is also a new one, not a 6 year old ball.
This seems to likely be the culprit.
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I think the doctor shorted me 3/1000 of something when I was born...at least that is what the wife claims must have happened.
3835
Trying to pretend its the difference in wearing a regular vs a magnum condom? I'd go with that lol
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On a side note, Tommy are you the guy who was on here complaining a while back about the different core specs between 15 and 14 lbs bowling balls? Where the 15 may have a rg of 2.54 and the 14 being 2.57 and how you couldn't use a ball at 2.57 and was upset because the 15 had the desired rg? It was in reference to a storm ball and I was just curious.
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The HyRoad is also a new one, not a 6 year old ball.
This seems to likely be the culprit.
How so do you mean? Other than color, it's basically the same cover(other than maybe slight percentages in solid to pearl ratio when the cover was poured). Notice I said, it's a new HyRoad, just like a new Rocket.
Old HyRoads are different than new Hyroads.
New HyRoads us current materials, just as the Rocket would.
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So I understand correctly, your assessment is that 3/1000" is the difference between a strike and a 2-8-10?
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On a side note, Tommy are you the guy who was on here complaining a while back about the different core specs between 15 and 14 lbs bowling balls? Where the 15 may have a rg of 2.54 and the 14 being 2.57 and how you couldn't use a ball at 2.57 and was upset because the 15 had the desired rg? It was in reference to a storm ball and I was just curious.
Not sure what you are talking about.
I believe in using high Rg low flare balls with weaker layouts and covers; and smooth surface for drier conditions, and low Rg balls with high differential with strong drillings and covers; and more surface for oil. Medium falls right in between. Really simple. Interestingly enough, that is how most companies design their equipment. I wonder why?
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So I understand correctly, your assessment is that 3/1000" is the difference between a strike and a 2-8-10?
Doubt it. I think 1/32" or .032, which is 3/100 of an inch at the pin deck could be enough change in angle to not ring a corner or be enough to touch the 3 pin for lefties or 2 pin for righties. It's all about the defection, and angle.
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You said that in your explanation of the differences between the HyRoad and SkyRocket no?
I'm sorry but if when it's all said and done, your final assessment of why one didn't strike over another is that minuscule of a mass...and nothing else...interesting
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You said that in your explanation of the differences between the HyRoad and SkyRocket no?
I'm sorry but if when it's all said and done, your final assessment of why one didn't strike over another is that minuscule of a mass...and nothing else...interesting
Do you know the difference between .03, and .003?
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On a side note, Tommy are you the guy who was on here complaining a while back about the different core specs between 15 and 14 lbs bowling balls? Where the 15 may have a rg of 2.54 and the 14 being 2.57 and how you couldn't use a ball at 2.57 and was upset because the 15 had the desired rg? It was in reference to a storm ball and I was just curious.
Not sure what you are talking about.
I believe in using high Rg low flare balls with weaker layouts and covers; and smooth surface for drier conditions, and low Rg balls with high differential with strong drillings and covers; and more surface for oil. Medium falls right in between. Really simple. Interestingly enough, that is how most companies design their equipment. I wonder why?
Some guy was on here complaing he couldn't throw a new storm ball because in 14lbs the rg was 2.57 and balls with rg that high rolled bad for him, but in 15lbs the ball had a rg of 2.54 and that rg he could throw.
Was just curious.
3/100" we should factor in the ball logos that are engraved vs the ones that aren't. That may be the bigger factor
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If I shift the pin placement 1/2" over and a 1/2" up, from the center of my grip, is it still a Rico layout?
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There are no layouts merely flare management
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There are no layouts merely flare management
Good one!!
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I just find it so fascinating how some posters keep reading three one-hundredths as three one-thousandths.
:)
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In ball reaction or motion and humans it doesn't matter
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Tommy, I assumed from what I posted and what you read you'd apply that SURFACE being the main culprit as ballreaction when I had said about drilling a ball anyway you want to....
You really need to get w/ the Phoenix Ball Balancing guy if this is how you perceive all the guys here giving their input and nobody is right here..
Ric Hamlin may come across arrogant, but really is it all that hard to comprehend what he's saying? There are #'s to back up what he's saying and he's been in the business quite awhile..
Say what you will, I'll trust Ric's input over anyone else's here (keep an open mind that's how you learn cgnomaddah)..
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No where, anywhere did I disagree that surface is the primary factor in ball motion. I know that, I agree with that. I'm just adding that the core plays apart in the equation, and the core is definable with numerical values, and those numerical values are Rg, differential and intermediate differential. If you think that has absolutely nothing to do with ball motion, feel free to believe that. I disagree. Ric ' s argument with me is that differential only matters, BUT and you can't have one without the other. No difference in Rg plains, then no difference in differential. The Rg don't matter is contradicting.
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Core differential has a much larger impact than RG ever will, that is and will be my contention...end of discussion
I relate cover stock and core differential to bowlers attributes plus layout with my decisions
These effect how the ball goes through the pins...in my limited experience
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Differential = flare potential... which equates to ball motion, so yeah I can understand Ric's assessment on that..
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I thought there were no layouts, only flare management? ??
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Core differential has a much larger impact than RG ever will, that is and will be my contention...end of discussion
I relate cover stock and core differential to bowlers attributes plus layout with my decisions
These effect how the ball goes through the pins...in my limited experience
+1 .... Core Differential is one of the first things I look at when vewing a ball I might be interested in. High differential balls work great for me as I need flare .... Low differential balls don't ...
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Can't have the differential without a difference in Rg plains. Good luck making a tropical breeze flare like a Crux.
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Not a shot you Tommy, but I always find it interesting that some people will hang on to piece of information that means little by itself. I know a guy who makes all of his decisions on rg. He'll watch me throw a few shots and say I'll leave a few 4 pins. Instead of adjusting my line or release, he'll suggest I use a ball with a slightly higher rg, even if it's from a different manufacturer with a completely different cover and surface.
If you're a machine or a top 10 pro, maybe you can read the difference between balls with and rg of 2.54 vs. 2.57, but why would you care? There are tons of adjustments I'd consider before rg in and of itself. I know the game has become very equipment driven, but isn't that excessive?
I skimmed over a lot of this and forgive me if it's already been covered, but doesn't the rf and diff. change after a ball is drilled? So unless have the same ball with the same drilling, but somehow with only a slight difference in rg, what are we discussing?
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Damn.....and all this time I was thinking it was operator error being the reason I left a 10 pin when it was RG all along. ;D ;D :P
I'm a bowler, I knew it couldn't be me. :P :P
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Wow talk abt thick headed and I'm the arrogant one...some get some don't
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Wow talk abt thick headed and I'm the arrogant one...some get some don't
Hey pot, this is kettle. ..
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I thought you were RG...
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Btw my alleged thick headedness (experience) comes from over 30 yrs in the bowling industry studying under the likes of Bill Wasserberger and Ray Edwards as well as being on the PBA tour and forming my opinions off of the results from CATs and numerous situations....if you want to think of me as arrogant or egotistical so be it...I appreciate those that respect my opinions and help
Signed the diff kettle
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Tommy, so the whole point was to figure out how to make a Breeze flare like a Crux? You realize they're not made the same?
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You could potentially create the same amount of flare merely by managing flare...one may require a 5" pin to pap (Crux) when the other may require a 3.375"in to pap (Breeze)
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Btw my alleged thick headedness (experience) comes from over 30 yrs in the bowling industry studying under the likes of Bill Wasserberger and Ray Edwards as well as being on the PBA tour and forming my opinions off of the results from CATs and numerous situations....if you want to think of me as arrogant or egotistical so be it...I appreciate those that respect my opinions and help
Signed the diff kettle
Thanks for that Mo.
I've since forgot is this in reference to RG or Diff? The op started on one then went to the other.
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Yeah thats it!
LOL!
I think the doctor shorted me 3/1000 of something when I was born...at least that is what the wife claims must have happened.
3835
Trying to pretend its the difference in wearing a regular vs a magnum condom? I'd go with that lol
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Damn.....and all this time I was thinking it was operator error being the reason I left a 10 pin when it was RG all along. ;D ;D :P
I'm a bowler, I knew it couldn't be me. :P :P
;D ;D ;D ;D ;D ;D ^^^^^^^^^^^^ ;D ;D ;D ;D ;D ;D
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For the OP lefty50 here is an example using an Track 607A which wouldn't really be considered asymmetric due to the weak int diff but the rg and diff are in the ball park of what you are talking about for not being able to work for you. If you give me your actual stats for everything I can plot some different things using BP software but for the time being here is the affects drilling and weight holes will have on a ball especially the Diff and Int Diff.
Ball undrilled stats
(https://www.ballreviews.com/proxy.php?request=http%3A%2F%2Fi250.photobucket.com%2Falbums%2Fgg252%2Fsoundcontrol%2Fexblank.jpg&hash=3931baf08d772879d7eeeaa50423db15b7d60830) (http://s250.photobucket.com/user/soundcontrol/media/exblank.jpg.html)
Ball drilled
(https://www.ballreviews.com/proxy.php?request=http%3A%2F%2Fi250.photobucket.com%2Falbums%2Fgg252%2Fsoundcontrol%2Fexblank-drilled.jpg&hash=bef23e0736baa0edb4d136efd1379cfa558e420f) (http://s250.photobucket.com/user/soundcontrol/media/exblank-drilled.jpg.html)
Ball with a small weight hole
(https://www.ballreviews.com/proxy.php?request=http%3A%2F%2Fi250.photobucket.com%2Falbums%2Fgg252%2Fsoundcontrol%2Fexblank-drilled-xhole1.jpg&hash=d28d40b53a904e9d82145f65bbca0de8841b53ad) (http://s250.photobucket.com/user/soundcontrol/media/exblank-drilled-xhole1.jpg.html)
Ball with a larger weight hole
(https://www.ballreviews.com/proxy.php?request=http%3A%2F%2Fi250.photobucket.com%2Falbums%2Fgg252%2Fsoundcontrol%2Fexblank-drilled-xhole2.jpg&hash=83839f066a76596a24641379599a487e4d2766d3) (http://s250.photobucket.com/user/soundcontrol/media/exblank-drilled-xhole2.jpg.html)
Notice how undrilled the diff was .049 and after drilling and a wight hole it is up to .062
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I think we can dispute the effects of Rg & differentials on pin carry but there is no
dispute as to the physics behind it all.
Rg alone does not give us enough information on a ball's ability to rev up. Neither does differential. They are directly dependent on one another only if we know the MASS of the imbalance.
Of the 2, Rg has a significant influence because it determines the DISTANCE of the core's imbalance from
its axis of rotation. The simplest formula that describes this relationship is:
I (moment of inertia)= mr^2 . where m = mass of the imbalance r= distance of the imbalance from its axis of rotation. This is just one of many formulas that determines
an object's moment of inertia----the most important factor in determining a ball's
resistance to "rev-up". These formulas vary, depending on the shape of the object
(i.e., sphere, cylinder, fixed rod, etc.) in question. The important thing to notice is that in the formula the quantity "r" is squared. This means that any change in a core's center of mass is not linear. This is significant because a change of say, 2.52 in a ball's Rg to
2.47 is not .005 but is .250 (two hundred and fifty thousandths--a full 1/4 inch).
Don't let core design confuse you as to its effects when it come to determining
a ball's moment of inertia. In the end, it's the mass (weight) of the imbalance
and its distance from the PSA (Rg) that count in determining a ball's ability (or inability) to "rev up".
Now when it comes to a ball's ability to flare, this is where differential
does play a big role, because it measures a ball's "wobble" (precession) about the
axis of rotation. Here, an asymmetric core that has asymmetry about all 3 axes
PLUS having a large intermediate differential, will maximize flare , depending on how it's drilled.
So, what does all of this actually signify? It signifies that if you take 2 similar balls
and for example, drill one with 2.52 Rg and the other with 2.47 Rg, The ball with the lower Rg WILL noticeably rev-up much quicker than the one drilled at 2.52 Rg.
On the other hand, doing the same with 2 dissimilar balls will not necessarily
produce the same moment of inertia (again, the most important quantity in determining a ball's ability to rev-up) even though they might both have the same Rg. The reason for this is that we simply don't know the mass of the imbalanced force . Differential alone doesn't tell us this quantity either.
For these reasons, I was never very fond of ball manufacturers' use of "Rg" alone, in trying to describe a ball's "rev capabilities". Some balls with an Rg of 2.50 will
rev faster (or slower) than another ball with 2.50 Rg but with a different mass that the first ball.
Also, when it comes to bowling ball dynamics, there are situations where indeed,
small changes can add up to big differences in performance. One of these quantities
is a ball's pocket (entry) angle. A 2-3 degree difference in entry angle looks insignificant on paper, but is anything but when it comes to its effects on pinfall.
Once again, it's the "physics" behind these numbers that will always, without fail,
determine its effects on ball motion/pin carry/ etc.
On the contrary, there is an article in the latest BJ about the effect of lane topography
on ball motion and performance. Here I would argue that the amount of lane tilt
(in any direction) would have at the very very best, a negligible effect on ball performance. Here, I am restricting my disagreement on TILT alone. This disagreement applies only to situations where the tilt is still within USBC tolerances and with balls thrown at normal velocities (and not balls rolled down ramps, etc.).
At lane tilts of .040 (maximum USBC tolerances), the amount of (ball) acceleration
(or deceleration) would be very very miniscule and would have no overall effect.
If the tilts were extreme, then there would be an effect, but these tilts would have to be MUCH MORE than .040 to even begin to have any effect on ball motion down the lane. The angle (slope) of a .040 incline is only .191 degrees ( less than 2 tenths of a degree). The acceleration/ deceleration of a ball would be so tiny as to be insignificant, especially when considering how little time the ball spends traveling from release to the pins. It would take a ball rolling DOWN such a ramp approximately 18 seconds, at which time it would have accelerated only 0.387 mph in the direction of the slope. Quite insignificant.
So the upshoot of all of this is that numbers can have a significant effect depending on
what it is you are attempting to measure. Sometimes it just takes a small quantity to make a measureable difference. Other times, it does not.
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bergman,
Out of curiosity, when measuring the MOI of the bowling ball, wouldn't you use the average Rg? If that is the case, then a ball with a low Rg of 2.50" and a differential of 0.060" would have the same MOI as a ball with a low Rg of 2.52" and a differential of 0.020".
But in the long run, isn't all this bickering over pre-drilled mass properties irrelevant? If a bowler wants a low Rg final product, can't they achieve that with specific drilling patterns and hole placements?
Maybe I am a noob who doesn't understand.....
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^^^bingo^^^
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bergman,
Out of curiosity, when measuring the MOI of the bowling ball, wouldn't you use the average Rg? If that is the case, then a ball with a low Rg of 2.50" and a differential of 0.060" would have the same MOI as a ball with a low Rg of 2.52" and a differential of 0.020".
But in the long run, isn't all this bickering over pre-drilled mass properties irrelevant? If a bowler wants a low Rg final product, can't they achieve that with specific drilling patterns and hole placements?
Maybe I am a noob who doesn't understand.....
Ok so just to make sure I'm understanding the line of thinking and maybe I'm taking this out too far does the predrilled Rg not even matter you can get anything you want through drilling and holes?
I do realize the beginning argument here was over a .03 difference in Rg but how far does this go out?
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Ric, where was my bingo when i said the earlier? :P
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I missed it
^^^^BINGO^^^^
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bergman,
Out of curiosity, when measuring the MOI of the bowling ball, wouldn't you use the average Rg? If that is the case, then a ball with a low Rg of 2.50" and a differential of 0.060" would have the same MOI as a ball with a low Rg of 2.52" and a differential of 0.020".
But in the long run, isn't all this bickering over pre-drilled mass properties irrelevant? If a bowler wants a low Rg final product, can't they achieve that with specific drilling patterns and hole placements?
Maybe I am a noob who doesn't understand.....
An object with two very different Rg plains (high differential) will have more instability as it spins. An object that is stable and has close or the same Rg's about the axis, will have a very predictable spin. So in order for you to have your theory of the low Rg drill/ high Rg drill be effective, you need to have a wide variation between the axis, hence Rg mattering to create the differential that you are looking to be able to use.
If it were as simple as what you are trying to make it, ball companies would not spend all the money they do on different shapes and densities of cores. They would use one core, and change the cover stock, and layout to accommodate. Basically, what Lane #1 used to do with their original diamond core.
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Tommy, didn't you just mention differential?? So now you're flip flopping between high/low rg and differential?
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bergman,
Out of curiosity, when measuring the MOI of the bowling ball, wouldn't you use the average Rg? If that is the case, then a ball with a low Rg of 2.50" and a differential of 0.060" would have the same MOI as a ball with a low Rg of 2.52" and a differential of 0.020".
But in the long run, isn't all this bickering over pre-drilled mass properties irrelevant? If a bowler wants a low Rg final product, can't they achieve that with specific drilling patterns and hole placements?
Maybe I am a noob who doesn't understand.....
An object with two very different Rg plains (high differential) will have more instability as it spins. An object that is stable and has close or the same Rg's about the axis, will have a very predictable spin. So in order for you to have your theory of the low Rg drill/ high Rg drill be effective, you need to have a wide variation between the axis, hence Rg mattering to create the differential that you are looking to be able to use.
If it were as simple as what you are trying to make it, ball companies would not spend all the money they do on different shapes and densities of cores. They would use one core, and change the cover stock, and layout to accommodate. Basically, what Lane #1 used to do with their original diamond core.
Or given the ranges USBC requires cores to be bowling companies try to manipulate differential and axis migration to achieve different shapes along with coverstocks.
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Tommy, didn't you just mention differential?? So now you're flip flopping between high/low rg and differential?
No Brad, I am not flip-flopping. I have been saying since my first post in this thread, that it is all connected. Ric is doing his best to convolute what I have been posting. Please go re-read my posts. I have maintained that they all have their parts of the equation.
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I have not convulated anything I've merely pointed out what is relevant and what isn't in ball reaction/motion...
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Both rg and diff have been mentioned through out with int diff not so much. As seen with the pics I've posted from bp software all will change a little to a lot depending on drill, and then adding xholes to the equation.
If a bowler thinks cores with this rg or diff will not work for them it never will because its a built in excuse and expectation not to work same for many who say asymmetric cores don't work for them but adding a motion hole, dual thumb, or other aggressive weight hole to a symmtric core is great……. Really. Let them limit their self and their options. Lot of great bowling balls they will miss out on.
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Spmcgivern:
The final drill determines the ball's true dynamics. Regarding your question on moment of inertia (MOI), the core differential numbers don't tell us anything about
the MOI. Remember that MOI (I) =m r^2. So to calculate MOI, we need to know:
The MASS (or weight) of the imbalance
Its distance from its axis of rotation or, Rg
The numbers we see on a ball's specs that are designated as the ball's Rg and differential, such as when a ball is marked as 2.50 Rg and .060 differential simply
tell us DISTANCE. They tell us nothing about the mass of the imbalance.
The engineers who design these balls have to know these quantities in order to be able to determine exactly how a ball will actually react at a specific RG number.
Again, the equation above is a bare bones one because one has to take into effect
the total SUM of the imbalances along all 3 axes (in short, the differentials), that when combined and multiplied by the square of the distance of the center of mass of all 3, will yield a ball's MOI, the quantity that tells us about a ball's ability (or inability) to rev up.
In addition, each ball is limited in how much "Rg" can be had, for the lack of a better term, depending on core and to a lesser extent, shell composition considerations.
Again, I was never a fan of the oft quoted "Rg" as being the SOLE factor in determining a ball's rev capability. It's like asking how long it would take one to travel
say, 10 miles without knowing the traveler's velocity. To equate this to a bowling ball, the "10 miles" would be the Rg. and the velocity would be the mass of the of the imbalance.
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It's one of those situations that if the bowler didn't know they wouldn't know...
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Measuring MOI is indeed, very predictable, whether the rotating mass is close to
its axis of rotation or if it is some distance away from it. The differential "number"
(.048, .060, etc.) matters not in determining MOI. It has more effect on a ball's ability to flare (precess) . For MOI, what matters is the weight of the imbalance coupled with its distance from the axis of rotation.
There are other factors related to a rotating bowling ball such as its angular velocity and torque, and although related, they alone, do not determine a ball's ability to rev up MOI does this perfectly.
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Justrico-- lol. Agreed!
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Very similar to if each bowling ball was a dark solid color they couldn't tell the difference especially on a house shot
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It's one of those situations that if the bowler didn't know they wouldn't know...
Core pictures and numbers are there to try and sell bowling balls to people who have no idea what they mean. No different then putting drill sheets in the box. Both are bad ideas, and common practice.
If a manufacturer tells me a ball is designed for dry lanes I'm not going to look at the core numbers and argue it isn't and pick another ball. Same for the other way around.
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Too many assume everything is absolute or competed in a vacuum...this is why surface is responsible for 70-75% of reaction...if surface doesn't match up properly then 'your' core numbers are irrelevant...more non-strikes are caused by inconsistency of the bowler plus improper surface
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^^^ bingo ^^^
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^^^ bingo ^^^
I need to play with the same numbers you guys do. :)
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Will all of you people please hold up for a few minutes as I ran out of popcorn and need to go get some more. ;D
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Let's regroup here........
Higher rg balls "tend" to go longer before going into a roll....
Now do you know why ball companies put higher rg cores into those bowling balls now?
THEY WOULD HOOKOUT at your feet w/ the coverstock on them that are made today..
You put a lower rg (I loved 2.44 to 2.46 cores but they were pearl coverstocks from 15yrs ago) into a coverstock like today it would rollout at the arrows..
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Surface.
Ball manufactures design bowling balls and tell you the intended purpose. Doesn't matter what the core is, if they say its their heavy oil ball its all factored in. If you "can't" use a ball because of a core then don't.