win a ball from Bowling.com
« previous next »
Pages: [1]

Author Topic: Another Double thumb qs?  (Read 1553 times)

wei

  • Jr. Member
  • **
  • Posts: 54
Another Double thumb qs?
« on: July 01, 2009, 11:57:18 PM »
I got my Virtual Gravity (tw: 3.38oz, PAP 5.5" x 3/4" up) drilled 45* x 4" x 35* by my proshop friend. He also mention that the ball is having 1 1/2oz of extra sideweight, so I need to drill a balance hole and he reckoned to put it on the PAP. But I decided to do that later because I just heard of the Double thumb balance hole techniques. So to be sure of it, can you guys help me with the qs below?

Can I really use the double thumb on this ball? Where would the position be? somewhere 2" from the thumb at 1" pitched to the right to make it legal? Also I read that the ball has be around 3.5oz-5oz topweight, is 3.38 ok?

(btw, I got lost when reading Mo's Gradient line technique, the only thing I understand was, max reaction i.e. flare and roll is achieved when the hole is drilled at the MB sign P4. Is that correct?)
Logged

 

BKloss

  • Sr. Member
  • ****
  • Posts: 266
Re: Another Double thumb qs?
« Reply #1 on: July 02, 2009, 08:12:39 AM »
What is the Finger/Thumb weight?

If you put a hole down in the thumb quadrant and it is already 3/4-1oz finger weight dual thumb is probably not the way you want to go.
--------------------

 
Logged

wei

  • Jr. Member
  • **
  • Posts: 54
Re: Another Double thumb qs?
« Reply #2 on: July 09, 2009, 11:54:03 PM »
Finally got time to log in.
The ball was having 1 1/4 oz finger wt and 1 1/2 +ve side wt.
So, cannot do dual thumb?
Logged

J_Mac

  • Hero Member
  • *****
  • Posts: 6778
Re: Another Double thumb qs?
« Reply #3 on: July 10, 2009, 12:04:43 AM »
quote:
Finally got time to log in.
The ball was having 1 1/4 oz finger wt and 1 1/2 +ve side wt.
So, cannot do dual thumb?


Nope.  You have too much finger weight to legally put the balance hole in the positive thumb quadrant.  My guess is that the pin out isn't long enough to make the double thumb layout possible.

In the future it would be in your best interest to have a pin-out of more than 4" to keep the CG in the positive thumb quadrant making it possible to place the balance hole in the position needed for a double thumb layout.

The USBC is considering a repeal of the static weight rules, but there is no telling how long it will take before this occurs.
Logged

wei

  • Jr. Member
  • **
  • Posts: 54
Re: Another Double thumb qs?
« Reply #4 on: July 10, 2009, 07:57:50 AM »
Thank you for the replies.

Lesson learned
Logged
Pages: [1]
« previous next »