Author Topic: Mass Bias Questions (Read 790 times)

billy2gun · « **on:** October 02, 2007, 02:46:06 AM »

I have some questions regarding mass bias (MB)

1. Do all reactive balls have a mass bias?

2. I read in another post that if the MB is placed under the thumb hole, the ball reaction is more smooth with more arc. If the MB is placed to the right, more length, more angular reaction. Is this true with all balls that have a mass bias?

For example, if you took a Black Widow, The Break, and a NVS and placed the MB to the right of the thumb hole, would all balls have more length and angular reaction?

3. How does having a MB help? In other words, is it better to have a ball with MB versus one without?

Thanks,
Billy
--------------------
"It is good that warriors such as we meet in the struggle of life... or death. It shall be life."

-The Outlaw Josey Wales

Dan Belcher · « **Reply #1 on:** October 02, 2007, 11:01:43 AM »

Before someone more knowledgeable clears up the details, I will give you this much knowledge: the mass bias is a measure of asymmetry. Assymetrical core balls have a point where the mass is more focused than others, that's where the MB is marked on the ball. Symmetrical balls have a mass bias of 0 or incredibly close to it, making it negligable, and it is not even marked on the ball.

Now, I'll leave it up to the people who know more about drilling to explain what it can do for you.

shelley · « **Reply #2 on:** October 02, 2007, 11:27:07 AM »

quote:
1. Do all reactive balls have a mass bias?

No. Being reactive has nothing to do with it, though you'll have to look far and wide to find a non-reactive ball with a mass bias.

Edit: Some will say that every pin-out ball has a mass bias. Perhaps that's technically true. But if it doesn't spin up in a reasonable amount of time then the mass bias isn't strong enough to bother with. Usually less than about 8s on a deTerminator. Mid-diffs above about 0.012-0.015.

Also, kinda hypertechnically, being symmetric or asymmetric doesn't necessarily have anything to do with it. There are very asymmetric cores (the Bully core, some of Ebonites weirdo cores like the "Y" propeller core) that have negligible mass bias strengths and some symmetric cores like the Centrex core from The One series that are extremely strong (the trick with the Centrex core is density, not shape).

quote:
2. I read in another post that if the MB is placed under the thumb hole, the ball reaction is more smooth with more arc. If the MB is placed to the right, more length, more angular reaction. Is this true with all balls that have a mass bias?

Under thumb, right of thumb, far right of thumb is not the best way to think about it. Distances from PAP or the PAP-pin-MB angle are what determine the reaction. The former does not take the PAP into account, and you simply cannot rely on a drilling that ignores the PAP. Especially for modern strong asyms.

Longer MB-to-PAP distances (more angle) (usually ends up with the MB under or left of thumb but depends on PAP) are usually more arcy while shorter MB-to-PAP distances are more angular. Closer to the PAP (less angle), like you'd get by placing it far right of the thumb, gives a hook-set type of reaction. The length is nominally controlled by the pin-to-PAP distance and the pin height (or pin buffer; pin-to-VAL).

It is true in that there are standard asymmetric layout techniques, just as there are for symmetric balls. How angular, how flippy, how smooth depends on the coverstock and the core shape, too. You won't make a GP2--a strong asym with more particles than you can shake two sticks at--flippy by putting the MB in some magic location (unless that location is on an Xception).

quote:
For example, if you took a Black Widow, The Break, and a NVS and placed the MB to the right of the thumb hole, would all balls have more length and angular reaction?

Putting the MB 3-4" from the PAP at 60-75* will make it more angular than at 5" from PAP at 90*, but only if you have two Breaks drilled like that. An NVS at 90* may be flippier than a Break at 60* (who knows?) because of the properties of the core, cover, and surface finish.

quote:
3. How does having a MB help? In other words, is it better to have a ball with MB versus one without?

The MB is just another reaction tuning mechanism, like pin-to-PAP, location and size of a weight hole, surface changes,... When people try to quantify the effects of various parameters on ball reaction, the MB has about half the influence of the pin, which is maybe a quarter of the influence of the surface prep. Surface prep might be 80%, the pin at 10%, MB and weight holes are around 5%.

It can help, particularly if you're consistent with your release. If every shot is different and your PAP is just a guess in a 1" radius circle, then not so much.
Insofar as there are cases of the "same" ball but one with an asymmetric core versus a symmetric core, the asymmetric version is usually slightly longer and more angular. The major case to look at is the Zone and Inferno lines from Brunswick. The Classic Zone and Original Inferno, the Vapor Zone and Absolute Inferno, the Strike Zone and Ultimate Inferno.

Some people match up well to asymmetric cores, some don't. Not all asymmetric cores are created equal, either. Some like asymmetrics, some like symmetrics. They each have their place and we have so many options because not everyone matches up with every ball. I haven't had an asymmetric since my Mutant, which is a medium-strength asym by todays standards. I liked that ball, I shot a lot of good (for me) scores with it. Since then, everything I've had is symmetric and I've been happy with them, too.

Buying a ball just because it's an asymmetric is wrong. Ignoring a ball because you are leery of it having a symmetric core is wrong. It's another piece of the puzzle.

SH

Edited on 10/2/2007 11:30 AM

Author Topic: Mass Bias Questions (Read 790 times)

billy2gun

Mass Bias Questions

Dan Belcher

Re: Mass Bias Questions

shelley

Re: Mass Bias Questions