Bowling ball core · Roto Grip

Roto Grip GEM A.I. Core

Asymmetric Roto Grip core

An asymmetric core with early rev-up and very high flare, built for heavy oil, medium to heavy oil. 1 of the 1 balls with this core are in stock at BowlersMart.

  • Asymmetric
  • RG 2.490
  • Diff 0.057
  • MB 0.017
Roto Grip GEM A.I. symmetric core shape inside the ball

Specs

RG AT 15 LB

2.490

Early rev-up

Revs soonerRevs later

32% of the reactive and urethane balls we stock have a lower RG.

DIFFERENTIAL AT 15 LB

0.057

Very high flare

Less flareMore flare

94% of the reactive and urethane balls we stock have a lower differential.

MASS BIAS AT 15 LB

0.017

Medium asymmetry

MilderStronger

54% of the asymmetric reactive and urethane balls we stock have a lower mass bias.

RG How soon the ball revs up.Differential How much the ball can flare.Mass bias How asymmetric the core is.
Roto Grip GEM A.I. Core specs by ball weight (reference ball: Roto Grip Perfect Gem)
Weight RG DifferentialDiff Mass biasMB
16 lb 2.490 0.055 0.017
15 lbUsed on this page 2.490 0.057 0.017
14 lb 2.520 0.056 0.016
13 lb 2.570 0.032 0.010
12 lb 2.590 0.029 0.008

Source: Roto Grip published specs, as listed on the Roto Grip Perfect Gem product page. RG and differential change with ball weight; use the row for the weight you throw. The highlighted 15 lb row is the one used on this page.

Balls with the Roto Grip GEM A.I. Core

1 of the 1 balls with the Roto Grip GEM A.I. Core are in stock at BowlersMart. Same core, different covers: pick the cover for the lanes you bowl on.

Roto Grip Perfect Gem Bowling Ball

Roto Grip Perfect Gem

Roto Grip E-R1 Solid Reactive

Heavy oil, medium to heavy oil

Sale price $199.95 Regular price $289.95In stock

Shop the 1 available balls with this core

Where the Roto Grip GEM A.I. sits

Each dot is a core in balls we stock. Cores close together roll alike; the cover and layout decide the rest.

Storm Element Tour A.I. Core, RG 2.470, diff 0.035DV8 Larceny Core, RG 2.471, diff 0.028DV8 Renegade Core, RG 2.499, diff 0.040Track I-Core Gen4, RG 2.480, diff 0.053Brunswick Vintage Light Bulb Low RG Core, RG 2.568, diff 0.032Brunswick Dual Centric Core, RG 2.509, diff 0.047Ebonite Big Time Core, RG 2.508, diff 0.054Hammer Stacked LED Core, RG 2.545, diff 0.047Hammer Vindicator Core, RG 2.474, diff 0.053Radical Vexed Variant Asymmetric Core, RG 2.490, diff 0.045Radical Modified Intel Symmetric Core, RG 2.483, diff 0.032900 Global Conduit A.I. Core, RG 2.590, diff 0.050Hammer Obsession Tour Core, RG 2.469, diff 0.034Hammer Super Offset Core, RG 2.524, diff 0.053Ebonite Turbo Core, RG 2.517, diff 0.040Ebonite Centrex Symmetrical Mass Bias Core, RG 2.466, diff 0.056Motiv Excel Core, RG 2.550, diff 0.030Motiv Detonator Core, RG 2.470, diff 0.055Storm Solarion A.I. Core, RG 2.480, diff 0.054SWAG Insanity Symmetric Core, RG 2.520, diff 0.034SWAG Fusion Core, RG 2.540, diff 0.036SWAG Watcher Symmetric Core, RG 2.510, diff 0.048SWAG Dragon Asymmetric Core, RG 2.490, diff 0.050SWAG Executioner Asymmetric Core, RG 2.500, diff 0.051Motiv Predator V2 Core, RG 2.470, diff 0.054Storm C3 Centripetal Control Core, RG 2.490, diff 0.029Hammer Vibe Core, RG 2.510, diff 0.042Hammer Aftermath Core, RG 2.520, diff 0.052Brunswick Alert Core, RG 2.478, diff 0.037Brunswick Rampart Core, RG 2.502, diff 0.051DV8 Collision Core, RG 2.462, diff 0.052Track MC2 Asym Core, RG 2.473, diff 0.046Radical Evil Eye Symmetric Core, RG 2.495, diff 0.046Ebonite Iron Fist V2 Core, RG 2.473, diff 0.053Radical No Doubt Symmetric Core, RG 2.485, diff 0.051Storm Surge Core, RG 2.580, diff 0.024Roto Grip Hyped UP Core, RG 2.500, diff 0.042Roto Grip Morph-Wing Core, RG 2.510, diff 0.051Brunswick Fury Core, RG 2.524, diff 0.038Motiv Sigma Core, RG 2.470, diff 0.047Roto Grip Hustle Core, RG 2.530, diff 0.030900 Global Blast A.I. Core, RG 2.470, diff 0.055900 Global Strobe A.I. Core, RG 2.510, diff 0.052Radical Guru Core, RG 2.503, diff 0.044DV8 Unholy Core, RG 2.504, diff 0.051Brunswick Infinity Core, RG 2.521, diff 0.051Storm Catalyst A.I. Core, RG 2.480, diff 0.053Hammer Gauntlet Core, RG 2.501, diff 0.050Hammer Raw Hammer Core, RG 2.537, diff 0.038Storm Atmos A.I. Core, RG 2.530, diff 0.042Storm Booster Core, RG 2.540, diff 0.046Track Shuttle Core, RG 2.480, diff 0.040Brunswick Light Bulb Core, RG 2.524, diff 0.030Radical Sneak Attack Core, RG 2.544, diff 0.036Motiv Gear Core, RG 2.480, diff 0.034Hammer Huntsman Core, RG 2.470, diff 0.050Hammer Super LED Core, RG 2.632, diff 0.034Ebonite Enhanced V2 Core, RG 2.480, diff 0.048DV8 Dualistic Core, RG 2.496, diff 0.045Radical Vexed Asymmetric Core, RG 2.498, diff 0.036Motiv Quadfire Core, RG 2.550, diff 0.043Brunswick Tiered Hexagon Core, RG 2.540, diff 0.045Columbia 300 Piranha Core, RG 2.554, diff 0.043Storm Torsion A.I. Core, RG 2.470, diff 0.050Storm Element Max A.I. Core, RG 2.470, diff 0.055Storm Radius Core, RG 2.610, diff 0.020Roto Grip Rondure Tour X Core, RG 2.480, diff 0.034SWAG Unreal Core, RG 2.510, diff 0.047SWAG Craze Core, RG 2.520, diff 0.030SWAG Serpent Asymmetric Core, RG 2.510, diff 0.048Radical Torpedo Asymmetric Core, RG 2.480, diff 0.052Motiv Overload Core, RG 2.480, diff 0.050DV8 Duality Core, RG 2.480, diff 0.036Hammer Spheroid Core, RG 2.480, diff 0.048Radical Outer Limits Asymmetric Core, RG 2.499, diff 0.051Motiv Apex Predator Core, RG 2.520, diff 0.055Brunswick Danger Zone Core, RG 2.501, diff 0.048Storm RAD-TQ Core, RG 2.560, diff 0.051Storm Velocity Core, RG 2.480, diff 0.051Hammer Modified LED Core, RG 2.586, diff 0.027Epic Spark Core, RG 2.540, diff 0.049Motiv Hadron Dual Density Core, RG 2.500, diff 0.045Track Criterion ID Core, RG 2.496, diff 0.047Brunswick Zone Asymmetric Core, RG 2.478, diff 0.048Ebonite Entity Core, RG 2.515, diff 0.052Roto Grip Rocker A.I. Core, RG 2.480, diff 0.050Motiv Flux Core, RG 2.570, diff 0.015DV8 Mantra Core, RG 2.498, diff 0.047Hammer Gas Mask Low Diff Core, RG 2.500, diff 0.034Roto Grip RST A.I. Core, RG 2.520, diff 0.055Motiv Impulse V2 Core, RG 2.550, diff 0.050SWAG APX V1 Core, RG 2.500, diff 0.042SWAG Judge Core, RG 2.490, diff 0.052900 Global Magna A.I. Core, RG 2.490, diff 0.044Columbia 300 Pulse PowerCOR Core, RG 2.468, diff 0.045KR Strikeforce Launch Core, RG 2.530, diff 0.047900 Global Ellipse Asymmetric A.I. Core, RG 2.480, diff 0.050Motiv Halogen Core, RG 2.550, diff 0.037Storm C3 A.I. Core, RG 2.480, diff 0.031Motiv Gear APG Core, RG 2.470, diff 0.036Radical Snapshot Symmetric Core, RG 2.523, diff 0.050Hammer Huntsman Tour Core, RG 2.472, diff 0.036Hammer LED Core, RG 2.650, diff 0.015Storm Inverted Fe2 Core, RG 2.570, diff 0.046Storm Capacitor Core, RG 2.570, diff 0.022Track I-CORE 3.0 (pictured: Track Paragon Fire Bowling Ball)1Track Stealth Core (pictured: Track Stealth Mode Hybrid Bowling Ball)2Hammer Gas Mask Core (pictured: Hammer Black Widow 2.0 Bowling Ball)3Roto Grip Rondure MaxD Core (pictured: Roto Grip Gremlin Bowling Ball)4Hammer High Rev Offset Core (pictured: Hammer 3-D Offset Assault Bowling Ball)5Motiv Affliction V2 Core (pictured: Motiv Raptor Reign Bowling Ball)6Roto Grip GEM A.I. Core (pictured: Roto Grip Perfect Gem Bowling Ball)EARLY REV-UPMID-LANELATER REV-UPHIGH FLAREMEDIUMLOW FLARE2.442.482.522.562.602.642.680.0100.0200.0300.0400.0500.060RG at 15 lbDifferential at 15 lb← Revs up soonerRevs up later →More flare ↑Less flare ↓

Nearest cores, zoomed in

Hover or tap a dot for that core’s numbers. Click a dot to open its page. Drag to move around when zoomed in. The same RG and differential do not guarantee the same ball motion.

This core 1 Nearest cores Other cores

Nearest cores to the Roto Grip GEM A.I. Core
Core Brand Shape RG Diff vs this core
Track Paragon Fire Bowling Ball1Track I-CORE 3.0Pictured: Track Paragon Fire
 Track Asymmetric 2.486 0.056 RG −0.004 · Diff −0.001
Track Stealth Mode Hybrid Bowling Ball2Track Stealth CorePictured: Track Stealth Mode Hybrid
 Track Symmetric 2.482 0.056 RG −0.008 · Diff −0.001
Hammer Black Widow 2.0 Bowling Ball3Hammer Gas Mask CorePictured: Hammer Black Widow 2.0
 Hammer Asymmetric 2.500 0.058 RG +0.010 · Diff +0.001
Roto Grip Gremlin Bowling Ball4Roto Grip Rondure MaxD CorePictured: Roto Grip Gremlin
 Roto Grip Asymmetric 2.500 0.058 RG +0.010 · Diff +0.001
Hammer 3-D Offset Assault Bowling Ball5Hammer High Rev Offset CorePictured: Hammer 3-D Offset Assault
 Hammer Asymmetric 2.489 0.053 RG −0.001 · Diff −0.004
Motiv Raptor Reign Bowling Ball6Motiv Affliction V2 CorePictured: Motiv Raptor Reign
 Motiv Symmetric 2.480 0.055 RG −0.010 · Diff −0.002

Matches use 15 lb RG and differential.

Drilling and tools

Drilling layoutsLayout guides for symmetric and asymmetric ballsDual angle converterTurn a pin to PAP layout into a dual angle layout

Turn on JavaScript to compare with your ball.Balls with the Roto Grip GEM A.I. Core1 of the 1 balls with the Roto Grip GEM A.I. Core are in stock at BowlersMart. Same core, different covers: pick the cover for the lanes you bowl on.

From Roto Grip’s description

Questions bowlers ask

What is the RG of the Roto Grip GEM A.I. Core?

At 15 lb the Roto Grip GEM A.I. Core has an RG of 2.490. It ranges from 2.490 to 2.590 across the listed weights.

What is the 14 lb RG of the Roto Grip GEM A.I. Core?

At 14 lb the RG is 2.520.

What is the differential of the Roto Grip GEM A.I. Core?

At 15 lb the differential is 0.057. The mass bias is 0.017.

Which bowling balls use the Roto Grip GEM A.I. Core?

Roto Grip Perfect Gem Bowling Ball. 1 are in stock now.

How do the Roto Grip GEM A.I. Core specs change by weight?

At 16 lb: RG 2.490, differential 0.055, mass bias 0.017. At 12 lb: RG 2.590, differential 0.029, mass bias 0.008.

How does the Roto Grip GEM A.I. Core compare with my ball?

Type the ball you throw into the Compare with your ball box on this page. It shows the RG and differential side by side and saves your bag for every core page.

Sources and method

Specs. Roto Grip published specs, as listed on the Roto Grip Perfect Gem product page, as published by the manufacturer.

Baseline. The baseline is 212 in-stock, published reactive and urethane balls. Plastic and polyester covers, 2-piece, 3-piece and pancake cores, missing covers and missing RG or differential values are excluded.

Percentiles. Percentiles are the share of baseline balls with a strictly lower or higher value; ties are not counted.

Nearest cores. Nearest cores are ranked by distance on standardized 15 lb RG and differential, with the same symmetric or asymmetric shape preferred among near ties (distance bands of 0.1).

Mass bias. Mass bias is compared among asymmetric balls with numeric mass bias only.

Updated. Catalog and page updated 2026-10-16.

Next lesson

Compare cores by RGEvery in-stock ball from lowest to highest RGCompare cores by differentialEvery in-stock ball from lowest to highest differentialAll bowling ball coresCore libraries for every brand we carryRoto Grip core libraryEvery Roto Grip core we have specs for