Drilling Gurus, I have a few questions regarding top weight. What is the effect of top weight on an undrilled ball? The reason I ask is that I have a bowler that swears that from previous experience only balls with starting top weight of greater than 3 oz. roll better for him. Does the top weight remain constant after drilling holes in a ball? I would think the top weight will either decrease or increase depending on the depth of the fingers/thumb. Does starting top weight have any bearing on how a ball rolls or matches up for a bowler? And should this be considered when buy a ball (i.e. 3 oz + top weight vs. 2 oz/2.5oz top weight)?

Any insight/information/thoughts on the subject are greatly appreciated. Thanks!

I cant speak for the ending top weight as I'm not quite sure how to determine it. I got a general idea but I'm not sure its right. For your friend, he must like weight holes but for most a 2-3" pin with a 2-3 oz top weight will do. These should be factored in when buying a ball for specific layouts. As i mentioned above, there are certain limitations of pin distance and top weight that will keep you from doing what you want and affecting the reaction of the ball. For example short pins for later transitioning layouts will force the driller to either pop a flare reducing weight hole or bury the fingers deeper.

With todays equipment the bowler that said he could tell a difference on balls that had more then 3ozs top weight prior to drilling is probably high. It really is that simple.

Yes. USBC allows  3ozs difference between the top half and bottom half of the ball.

http://www.bowlingfans.com/jeff/ballreactionbasics.html



Top/Bottom Weight
As mentioned previously, bowling balls come with extra weight placed under the center of gravity punch on the ball to balance out the weight taken out by drilling holes.  This weight is called top weight because it is located in the top of the bowling ball.  Bowling balls generally are manufactured with anywhere from two to four ounces of top weight although it is possible to find balls that fall outside that range.  Lightweight balls are made with less top weight generally for two reasons.  Light balls generally are drilled for children so the holes are smaller, meaning there is less weight removed that needs to be balanced out.  Also, since the ball has less total weight, an ounce or two of top weight will have more effect on the ball's dynamics and throw them "out of whack."
Top weight has a similar effect as finger weight: the ball will go longer down the lane and snap a bit more on the backend.  Likewise, bottom weight is like thumb weight in that it makes the ball roll earlier and arc more.
Unlike other static weights, ABC/WIBC regulations allow up to 3 ounces of either top or bottom weight.  This is measured on the dodo scale by comparing the drilled side of the ball (top) to the non-drilled (bottom) side of the ball.
Top and bottom weight are not necessarily caused by shifting the CG away from the center of your grip.  They are more a result of how much extra weight the manufacturer placed in one side of the ball and how much weight is removed from that side during drilling.  However, you can alter top weight and bottom weight by shifting the CG.  Because top/bottom weight are measured by comparing the grip side of the ball (the top) to the non-grip side (the bottom), if you shift the CG away from the center of the grip, you are moving it around the circumference of the ball towards the bottom.  You would be removing top weight (and/or adding bottom weight depending on how you look at it) by shifting the CG.  Therefore, the most top weight you can have in any particular ball after drilling (and before drilling any extra holes) would be if the CG is directly in the center of the grip.


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To the OP, what is the track of the bowler that said that?  I once had a driller tell me that because of my low track, that top weight would be like additional side weight for me.

The customer is always right (at least in their own mind).  If they want at least 3 oz STARTING top, then great...  They feel comfortable and satisfied, then all is well.  Keep in mind this is starting and once a layout is chosen and holes are put in the ball, it will change.  As stated above, higher starting top weights mean bigger weight holes (providing a the layout allows), which removes additional material from internals/core of the ball, resulting in altering the core dynamics.  Depending on the location of the hole, this could change reaction from a little to a lot.  So indirectly it could change reaction significantly, on its own, probably not much.

I still bowl with people who truly believe that their ball with "thumb weight" is only good for heavier oil patterns because it gets the ball into a roll earlier, yet they have no idea of the surface finish of the ball, the strength of the coverstock/core combination, or the actual layout of the ball based on their release stats.

S^2

Thank you everyone to your informative posts. I was able to set they guy up with a good arsenal and he is liking the setup. I talked to him that the biggest thing to influence a balls reaction is the surface. Although statics do factor in to some degree, the surface offered the biggest increase or decrease in a balls reaction. Again, I appreciate everyone taking the time to read and reply to my post.

When playing with the blueprint software, surface change showed to have biggest effect on the balls reaction.