Center of Gravity

Please keep this page as objective as possible, keep debates and subjective comments on the discussion page

CG punch on a bowling ball

Definition

Definition 1: The point marked on the cover of the ball, indicating where the most top weight is, to be used in the drilling process
Definition 2: The actual center of gravity close to the center of the ball
It has been claimed to affect ball reaction enough to be important to consider CG when considering Ball Layouts
Definition 3: Center of Gravity is not entirely accurate, the CG is typically a heavy spot on the ball for balancing purposes, the manufacturers place additional weight (known as top weight) to account for drilling, the punch mark approximates the spot where the ball when placed in a salt water solution "balances" itself, this is an approximation by the ball manufacturers as the "heavy spot" is down in the solution and the employee marking the ball has to measure 180* away from where they actually see it. The only true way to find this true zero zero point is to utilize a dodo scale.

Does CG Matter?

It's been an ongoing debate on internet message boards such as BallReviews.com to determine whether CG matters or not. Both sides, "CG Matters" and "CGNOMADDAH" have each come up with an argument stating CG's effect on ball reaction. Below is a recap of each side's point(s).

"CG Matters" View

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Work in Progress - Comments Welcome

The CG helps mark the Mass Bias on a Symmetrical ball. Although the strength of the Mass Bias is very low in a symmetrical ball, it is a Mass Bias, nonetheless, and helps more precisely layout a bowling ball.

Short and sweet, if you take into account the cg for any reason while laying out a ball (IE balance hole location, or reaction) then it matters. My personal belief is that certain styles of bowlers may see differing results out of cg/finger/thumb/side wieghts. If a 2" shift in the CG allows you 1 foot longer on a lane, it may indeed benenfit you. A slight variation in entry angle can mean the difference in carrying the ten pin or not. Recovery from the outside can be affected from cg placement (in my opinion even if it is a perceived motion, it is noticeable to the bowler)and bowling a lot of evenings is all about confidence.

"CGNOMADDAH" View

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Work in Progress - Comments Welcome

• 1 Ounce of static weight accounts for 1/256th of the entire weight of a 16 pound bowling ball.
• Shifting CG does NOT modify the orientation of the core.
• Shifting CG does NOT modify track flare OR move the bowtie.
• The effect of CG on ball reaction is less than the effect of bowler error, or the inability to repeat shots.
• Brunswick video lane plot shows "little or no difference" in ball reaction.

Consensus

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• CG matters in terms of keeping a bowling ball within the USBC guidelines for static weights after drilling.

Links

• Brunswick Throbot Video
• Lane #1 CG Video
• Nick Smith CG Video #1
• Nick Smith CG Video #2 @ USBC HQ
• USBC Test Results