Brilliant. Extraordinary. Magnificent. Call it what you will, but we prefer to call this beauty exactly what it is, a GEM™. Not only will its breathtakingly good looks mesmerize your competition, but its overall performance will as well thanks to the inner treasure known as the Defiant™ LRG Core - (the lowest RG asymmetrical core Roto Grip has ever created.) Which means this is by far the fastest revving asymmetrical core we have ever produced. And well, we couldn’t just stop there, so we wrapped this monstrosity of a core with the most aggressive solid coverstock we make known as MicroTrax™ Solid Reactive. Making this ball dazzle on those Heavier Oil Conditions.

Release Date: March 11th, 2022

Color: Citrine/Ruby/Amethyst
This kit contains:

Technical Specifications

  • 12 lbs.
    Radius of Gyration






  • 13 lbs.
    Radius of Gyration






  • 14 lbs.
    Radius of Gyration






  • 15 lbs.
    Radius of Gyration






  • 16 lbs.
    Radius of Gyration






Defiant LRG Core

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 Defiant Series of bowling balls which featured a core ahead of its time regarding flare migration in order to create a longer constant motion. Upon further review and testing, we found that by altering the composite of this core shape, we were able to create the fastest revving, strongest continuing, lowest RG asymmetrical core we have ever offered in the history of ever now known as the DEFIANT™ LRG CORE.

MicroTrax™ Coverstock

The MicroTrax (Micro Nanoparticle Traction) Coverstock offers the optimum balance of midlane traction and responsiveness to friction thanks the blend of nanoparticles throughout the coverstock. This formulation maintains its surface profile texture longer to ensure you get maximum performance while displacing oil at an above average rate compared to other coverstock materials on the market today.

Engineered for Medium/Heavy to Heavy Oil Conditions

Ball Reaction Section

Product Reviews
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Scotty Buts
August 10, 2022
Best ball from my sack!
This is hands down one of the best RotoGrip balls I have ever slept with! I am always going to hit 300 with this .... GEM!!!
0 of 0 people found this review helpful.
Scott Buttz
August 10, 2022
Great Ball!
I waited years in anticipation for this new ball. Upon arrival I broke into tears and couldnt believe the day finally came. When I opened the box the new ball smell hit me like the smell of rain on a spring day. I will never use another ball again and even consider sleeping next to it. Will keep you updated on how many 300s I bowl with this bad boy!!!
0 of 0 people found this review helpful.
Dana Knoop
July 30, 2022
This ball is a beast
So much drive! I throw the ball fairly slow but this think hits the pins like I threw it 20mph! Highly recommend!!
0 of 0 people found this review helpful.
Edward Hornyak
June 13, 2022
Gem Bowling Ball
Best performance bowling ball I have ever through
0 of 0 people found this review helpful.
Roto Grip Rick
May 14, 2022
A true GEM
Roto Grip GEM
Cover: MicroTrax Solid
Core: Modified Defiant Core
Factory Finish: 2000=grit
My Finish: 4K FAST
Layout: 55 x 2 x 55
Once I heard that the Defiant core was coming back, I was gitty as a kid going to his first tournament. Schlem and the crew at SPI change the core material a little bit to bring it up to today’s game. Matching the MicroTrax cover to this updated core has added some smiles back onto my face and more strikes in my game. First thing that POPS out is the awesome color choices. You KNOW when the GEM goes do the lane and it really does turn heads on the lane and off the lane. The GEM replaced for me the Roto Grip UFO with more overall continuous motion and also not as early in the front part of the pattern where the majority of the conditioner is located. The GEM moves so well in the front that the energy it stores is the best I have seen in some time for a solid reactive in overall carry and strength going into the pocket. The GEM works well on all lane panels, including wood. I cannot wait to use this, Storm Nova, Hyped Pearl and Roto Grip Helios at Nationals in late June.
0 of 0 people found this review helpful.
Wigg Faulkner
May 7, 2022
745, 772, 708 this ball is as amazing as the Defiant was and I'm a few years older now. Great ball!
0 of 0 people found this review helpful.
Jonathan K Saft
May 7, 2022
Best Ball Ever
I needed a ball to jump to the next level in my game and GEM is that ball
0 of 0 people found this review helpful.
roto grip gem
April 23, 2022
i love it
0 of 0 people found this review helpful.
Glenn Wendel
March 27, 2022
Gem - IT HOOKS !
Ball Specs:
Roto Grip Gem
Micro Trax Solid Reactive
Asymmetric Defiant LRG Core
Finish grit 2000 Sanded

Bowler Specs:
Right Hand. PAP 5” Over 1/2 up
Rev Rate 300. Tilt 20. Rotation 50.
Speed at release 17

This ball hooks! I am becoming more and more impressed with the Roto Grip Gem as I bowl with it. This ball out hooks everything I have including the Proton Physics. When I drilled my first Gem I left it at box finish and it was super strong and hit hard but I had to put it away quickly because as the lanes broke down it was too strong up front an lacked a bit of hit as I moved inside. I have since drilled another one weaker and polished it. The polish makes it look even better and makes it a more angular piece. This was after trying a 5000 wet sand finish which I really like also. The bit of polish helps me stay with this ball longer on heavy oil and I never loose angle. The Gem polished is still an early revving aggressive ball. I still have to ball down sometimes because this ball is so strong. The ball looks great going down the lane and even though it is multi-color I still can see the roll and motion very well on it.
Strong balls are easy to sell and we have moved a good bit so far and the customer feedback it very good. This ball never seems to skid too far and reads the breakpoint easily due to the strong core and cover enhancements Roto Grip has made. I am very happy to have this ball and have already had some big numbers with it.

The Gem hooks early and doesn’t stop.
The Ball has a great look.
This is a must have if you need a heavy oil ball.

Glenn Wendel
PBA Member
Storm Pro Shop Staff
0 of 0 people found this review helpful.
Gem oh yeah
March 26, 2022
Got my new Gem on 3-24-22 I just can't believe how well this ball performs. It hits like a tank messengers all over the place and it's colonization is stunning practice tomorrow will be fun exploring the balls talents and Monday night league should be interesting
0 of 0 people found this review helpful.
Mike Craig - Storm Products Amateur Staff
March 26, 2022
Gem review by Mike Craig
I drilled my Gem with a pin under layout of 30 x 4.5 x 70. The intent is to have something that is smoother than my PROTON PHYSIX and NOVA when the condition calls for staying on line with a strong ball. I have only thrown it box finish.

I threw my GEM on a 46 foot PBA pattern and on a league condition that always starts tight outside then breaks down in the fronts quickly. On the 46 foot pattern, the GEM was quick even with the pin down layout. I ended up having to separate my feet and target too much to carry well so I had to put it away. My NOVA was better on this pattern to carry with. On the league condition, the GEM's strong cover just ate thru the heavier oil. When it came time to move, the GEM was too much ball and just moving left into where everyone else had been playing made me have to get out of it quickly.

So what I can see so far is the GEM is very strong. It is right on par with the PROTON and REALITY as far as big hitters go. The few pin up lay outs I have seen go down lane are very continuous and don't quit. So if you want a big cover/engine ball that will cover some boards and hit well, then drill a GEM up!
0 of 0 people found this review helpful.
Matt Ward
March 24, 2022
Gem is a beast
I' am not the one to typically do reviews. However, The Gem is an exception. Started bowling about 3.5 months ago, and was struggling to break the 200 mark.

Last night I was able to throw back to back 200+ games with the Gem, and man this ball is a beast. Strongest, and most controllable ball I have ever thrown. I would recommend to anybody who needs a strong A-Symmetrical ball and plays more straight up.
0 of 0 people found this review helpful.
March 16, 2022
Gem is a great ball.
I am new to bowling and yes not the best ball for a beginner but I still love it. I will become more consistent with it as I practice but this ball hooks like crazy even when there is a lot of oil.
0 of 0 people found this review helpful.
Landen Lee
March 12, 2022
looks cool i need it for my 2 handed bowling
0 of 0 people found this review helpful.
Josh Shoemaker
March 7, 2022
Hey everyone, this is Storm staff member Josh Shoemaker here again with another ball review for the brand new Roto Grip GEM. As always, I would like to thank Storm for providing the equipment I use every time I step out onto the lanes and I Am Bowling for making sure I always look good no matter what! Today I will be bowling on a standard medium to higher volume house shot. This lane was just oiled with a fresh house shot. The GEM features Roto Grips lowest RG asymmetric core to date and is wrapped in microtrax solid. I will be honest, I’m not a huge fan of the color scheme on this ball. It’s a little tougher for my eyes to pick up ball motion when the colors are so vibrant. What I will say is I absolutely love what I see out of this ball so far. With how stable and early revving this core is, I expected it to slow down extremely quick and have next to no shape downlane. When balls do this, they tend to not go through the pins properly unless you’re on a ton of volume or crispy backends. The GEM provided me all the control I could need and wasn’t too lazy when it encountered friction downlane either. I’ve worked a lot lately on staying more compact as well as lowering the amount of axis rotation I use to help close down my angles more. The GEM does exactly what I want a ball to do on the fresh. It be amazing at blending out higher ratio patterns and controlling the pocket on tougher tournament patterns. I decided to go with a different layout than I usually do on my bigger and slower response asyms since I just recently drilled a fresh Proton PhysiX and didn’t want to see too much overlap. The GEM wants to go a little more forward off the end of the pattern and will play much better with closed angles whereas my Proton will do better from a little farther left. When compared to the RST-X1, the GEM is much earlier, stronger and creates a lot more friction overall. When compared to the Rubicon, the GEM is two steps up in terms of strength and friction created. Be sure to stop into your local Storm VIP Pro Shop and preorder your own GEM today for the March 11th release date!
Review Video:
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