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Author Topic: Gem  (Read 10487 times)


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« on: April 14, 2022, 08:52:37 AM »
The look and performance of this high-performance bowling ball make it nothing less than a Gem. The Roto Grip Gem introduces us to the Defiant LRG core which is the lowest RG asymmetrical core in the current Roto Grip line-up. This core enables the ball to rev up fast and continue strong! Not only is the core in this ball noteworthy but the coverstock is the extremely aggressive MicroTrax Solid Reactive. This powerful combination makes this bowling ball perfect for heavy oil conditions.

Color: Citrine/Ruby/Amethyst
All colors do vary somewhat from the picture shown
Coverstock: MicroTrax Solid Reactive
Core: Defiant LRG (14-16#)
Finish: 2000 Abralon
RG: 2.47 (for 15# ball)
Differential: 0.053 (for 15# ball)
Recommended Lane Condition: Heavy Oil
Hook Potential: High
Length: Middle


Luke Rosdahl

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Roto Grip Gem Review by Luke Rosdahl
« Reply #16 on: June 15, 2022, 07:41:57 PM »
The Gem features the MicroTrax Solid cover that we saw on the UFO, plus the inspired evolution of the Defiant core in the Defiant LRG, producing the lowest RG Roto Grip has ever had in a ball at 2.47.  The result is a very strong, heavy rolling and powerful asymmetric solid thatís the strongest ball Iíve ever thrown.  Despite this, itís somehow very usable, it doesnít see a lot of league action but on challenge and sport patterns, itís one of my go toís on the fresh, and being that Iím a lefty and see fresh on every pair I move to, itís something I can stick with in sweepers and can just move with in regular tournaments where we stay on the same pair.  It manages to hook a lot without burning up and hitting flat, I continue to find myself stunned at the versatility and power at the pins.  The Gem fits alongside the Reality and Proton PhysiX, it doesnít necessarily compete with them because they all have different shapes and slightly different hook potentials. 
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Re: Gem
« Reply #17 on: June 27, 2022, 12:31:35 PM »


The GEM is the strongest ball I have thrown to date. Because of that I didnít think it would leave the bag often but I was pleasantly surprised. I have used the GEM on a plethora of patterns and oil volumes. When it goes through the pins you can hear it on the other end of the bowling alley, it just doesnít quit. The color combo is not something I am in love with but at the end of the day the ball motion is something I canít see myself without. The GEM and Reality for me are the perfect compliments to each other and see a lot of lane time on sport patterns. I have found the more it lane shines the better it gets for me. It has proven to be more controllable.


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Re: Gem
« Reply #18 on: July 01, 2022, 06:11:44 PM »
RG: 2.47 Dif:0.053 PAS:0.016 Defiant Core with the MicroTrax Solid Cover at 2000
Layout: 4 ľ x 4 x 2 Rev Rate 275-300 PAP: 5 1/8 over 3/4 up.

I have always had issues with getting a ball to hook and finish on heavier volumes or longer patterns. I will say that my game has improve tremendously over the past couple of years Especially ball speed. That being is no lack of hook potential in the new GEM. This ball is a beast! The shape smooth and round with a strong backend motion. The GEM picks up down lane and drives hard through the pins. This has been a ball and motion I have been waiting on for a long time. Especially for a big cover/core ball for fresh heavier conditions. The GEM is good for those that like play straighter and still shape the ball down lane. Getting deeper in may have some difficulty making the conner and depending on style of play. If you are looking for a strong ball for the heavier/fresher patterns checkout the GEM at t your local VIP pro shop.


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Re: Gem
« Reply #19 on: July 05, 2022, 04:13:56 PM »
Gem - Ball Specs
Cover Stock: MicroTrax Solid Reactive Cover Stock
Finish: 2000 Grit
Core: Defiant LRG Core
RG: 2.47
Differential: 0.053
Intermediate Diff: .016

Pattern: Kegel Big Ben
Length: 44
Type: Sport


Likes: Strongest ball to date in the SPI lineup.

Dislikes: None

Big ball with big versatility options.
Drilled my standard Asym layout 50x5x10 for my lower rev rate gets the ball through the fronts for my power tweener style. After 30 plus games this is my go to ball on longer patterns and the fresh THS. The big core combined with the cover carve a bigger footprint than the Proton and Reality. More rolly and continuous down lane where you can immediately tell if you are carrying ten back.

Much to my surprise I enjoyed this release as much as my Reality. Always in my bag for all competition.


Keith Cordy
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Re: Gem
« Reply #20 on: July 07, 2022, 07:20:42 AM »
Big cover big core produces the strongest rolling ball on the market. The absolute 1st ball to pack for tournaments it handles the toughest of heavy oil patterns especially for anyone who likes to keep it in front of them. Definitely the leader in backend motion for any ball ever produced in this category.