Roto Grip

Roto Grip Gem Bowling Ball

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  • Roto Grip Gem Bowling Ball and Core
  • Roto Grip Gem Bowling Ball
  • Roto Grip Gem Bowling Ball Core
MSRP: $242.95
— You save $68.00


Roto Grip Gem Bowling Ball

  • Color: Citrine / Ruby / Amethyst
  • Coverstock: MicroTrax Solid Reactive
  • Weight Block: Paragon LRG Core
  • Factory Finish: 2000-grit Sanded
  • Flare Potential: High
  • Radius of Gyration (RG): 16lbs - 2.47; 15lbs - 2.47; 14lbs - 2.50
  • Differential (Diff): 16lbs - 0.051; 15lbs - 0.053; 14lbs - 0.052
  • Intermediate Differential (Diff): 16lbs - 0.016; 15lbs - 0.016; 14lbs - 0.015
  • Fragrance: N/A

Additional product information:

Sometimes evolution can spark new life into technology from yesteryear. Such is the case with our latest introduction to the HP4 Line of balls. With recent more in-depth studies of flare migration and core tendencies we circled the wagons back to the ParagonTM Core which was created based on axis planes in order to keep the core in constant motion longer.

Upon further review and testingwe found that by altering the composite of this core, we were able to create the fastest revving, strongest continuing, lowest RG asymmetrical core ever offered from Roto Grip now known as the PARAGONTM LRG CORE.

From there, we wrapped the Paragon LRG Core with our most aggressive coverstock material known as MicroTraxTM Solid Reactive making this the optimum ball choice for anyone and everyone on those heavier oil conditions.

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Additional Information

Lane Condition:
Factory Finish:
Sanded 2000 Abralon
Core Type:
Solid Reactive
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34 Reviews

  • 4

    I can play down and in or I can swing it great first game ball

    Posted by stanley b gibbs on Apr 13th 2023

    Great first game ball or Long oil

  • 5

    Rotogrip Gem

    Posted by Michael Cochran on Nov 2nd 2022

    Drilled 50x3.5x50 Very smooth rolling heavy oil ball. Drilling by Buddies is spot on. Very appreciative of their services. Thanks

  • 5


    Posted by Mancstorm on Jul 7th 2022

    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.

  • 5

    Big Bad RG Gem

    Posted by Keith Cordy on Jul 5th 2022

    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 LANE CONDITION Pattern: Kegel Big Ben Length: 44 Type: Sport COMMENTS 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 900 Global Staff Ambassador #GoGlobal #SquadRG #stormnation #12InARowProShop #CustomThumbzProshop

  • 5

    Must Have

    Posted by Rodney Gilmore on Jul 1st 2022

    RG: 2.47 Dif:0.053 PAS:0.016 Defiant Core with the MicroTrax Solid Cover at 2000 Layout: 4 ¼ 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 corner 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.

  • 5


    Posted by Kassy Shumate on Jun 27th 2022

    The GEM is the strongest ball I have thrown to date. Because of that I didn’t 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 doesn’t 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 can’t 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.

  • 5

    Roto Grip Gem Review by Luke Rosdahl

    Posted by Luke Rosdahl on Jun 15th 2022

    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 that’s the strongest ball I’ve ever thrown. Despite this, it’s somehow very usable, it doesn’t see a lot of league action but on challenge and sport patterns, it’s one of my go to’s on the fresh, and being that I’m a lefty and see fresh on every pair I move to, it’s 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 doesn’t necessarily compete with them because they all have different shapes and slightly different hook potentials.

  • 5

    RG GEM

    Posted by BRIAN HIRSCH on Jun 12th 2022

    Roto Grip GEM Ball Review Hey everyone, I’m back with another ball review, and this time it’s for the GEM and in 15 pounds this ball is wrapped in the Micro Trax Solid Coverstock and comes 2000-grit polish with an RG of 2.470 and a Diff of 0.053 and a PSA .016. Layout for this ball is 4x4x2 I have enjoyed when I am able to get this ball into my hands, but with bigger balls in my hand and the mid-dry I have at home I don’t get to throw this ball as much as I would like too. I keep this ball in my tournament bag and its really good when the lanes start with a higher volume or longer pattern. I can see this ball being thrown on a fresher condition with players with more hand. I am on the lower rev rate side and need the stronger balls to see the friction so with the right condition I can stay in the track a little longer than most before having to move. BOWLER STYLE: RH - Power Stroker Rev Rate: 320 Ball Speed: 15-16 PAP: 4 7/8 right 5/8 up. #Storm #SquadRG #900Global #VISE #BowlersChoiceProShop #BabesAndBallsBowling #LogoInfusion #IAmBowling (coupon code HIRSCH 20% off at checkout) YouTube Channel: Brian Hirsch

  • 5

    Roto Grip Gem review by Trevor Roberts

    Posted by Trevor Roberts on May 20th 2022

    The Gem is possibly the strongest ball in the Roto Grip line. For me, it was a little bit earlier and covered more boards than the Reality! Typically in the bigger asymmetric balls, you will see the ball burn all its energy in the front part of the lane, and go pretty straight down lane. But not the Gem! This ball retained way more energy than I thought it would, and went through the pins very well even from left of 20. I saw the Gem go down the lane a lot when I was on tour, and now I see why. If you want some additional length and energy, don’t hesitate to add some polish. Both Verity Crawley and Anthony Simonson used their Gems with polish, and they looked even better in my opinion.

  • 5


    Posted by Stnley Waite on May 19th 2022

    Gem - Ball Specs Cover Stock: MicroTrax Solid Reactive Cover Stock Finish: 2000 Grit Core: Defiant LRG Core Layout: 50 x 5 x 40 RG: 2.47 Differential: 0.053 Intermediate Diff: .016 Review The GEM is the latest addition to Roto Grips HP4 line of balls. Roto Grip circled the wagons back to the Defiant series to create the Defiant LRG Core by altering the composite shape of this core which makes it faster revving, stronger, and continuous, wrapped in the most aggressive MicroTrax solid reactive coverstock. Not only does this ball look great but it definitely throws it weight around. I tested the Gem on a 44 feet typical house pattern, I was able to play track area and deep inside with great success. The Gem reads early in the midlane and had a lot of energy on the backend for a continuous motion with great pin carry. This is a great ball for all levels of bowlers. Order one from your local pro shop today! My ball review videos are posted on YouTube channel Stanley Waite. Stanley Waite 900 Global Staff Member Dover, DE

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