Bowling ball core · Roto Grip

Roto Grip Defiant LRG Core

The core inside the Roto Grip Gem line

An asymmetric core with early rev-up and high flare, built for heavy oil. Balls with this core are no longer available at BowlersMart.

  • Asymmetric
  • RG 2.470
  • Diff 0.053
  • MB 0.016
Roto Grip Defiant LRG symmetric core shape inside the ball

Specs

RG AT 15 LB

2.470

Early rev-up

Revs soonerRevs later

2% of the reactive and urethane balls we stock have a lower RG.

DIFFERENTIAL AT 15 LB

0.053

High flare

Less flareMore flare

78% of the reactive and urethane balls we stock have a lower differential.

MASS BIAS AT 15 LB

0.016

Mild asymmetry

MilderStronger

33% 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 Defiant LRG Core specs by ball weight
Weight RG DifferentialDiff Mass biasMB
16 lb 2.470 0.051 0.016
15 lbUsed on this page 2.470 0.053 0.016
14 lb 2.500 0.052 0.015
13 lb 2.570 0.032 0.010
12 lb 2.590 0.029 0.008

Source: Roto Grip published specs, as shown on BowlersMart’s original Roto Grip Defiant LRG core page (2022). 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.

Looking for a ball like your Gem?

Balls with the Roto Grip Defiant LRG Core are no longer available at BowlersMart. These in-stock balls have the closest RG and differential.

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Hammer Reckoning Bowling Ball

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Motiv Forge Fuel Bowling Ball

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Storm Ion Max Pearl Bowling Ball

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Balls with the Roto Grip Defiant LRG Core

None of the 8 balls with the Roto Grip Defiant LRG Core are in stock at BowlersMart right now.

Show 8 balls no longer available at BowlersMart
More bowling balls with the Roto Grip Defiant LRG Core
Ball Cover First seen
Roto Grip Magic Gem Bowling Ball Roto Grip MicroTrax Hybrid Reactive September 2023
Roto Grip Exotic Gem Bowling Ball Roto Grip MicroTrax Pearl Reactive October 2022
Roto Grip Gem Bowling Ball Roto Grip MicroTrax Solid Reactive February 2022
Roto Grip Gem Hybrid Overseas Bowling Ball Roto Grip Hyper Response Hybrid Reactive June 2023
Roto Grip Purple Gem Overseas Bowling Ball Roto Grip MicroTrax Solid Reactive June 2023
Roto Grip Gem Pearl Overseas Bowling Ball Roto Grip Hyper Response Pearl Reactive December 2022
Roto Grip Gem Crystal Overseas Bowling Ball Roto Grip Hyper X Hybrid Reactive November 2024
Roto Grip Gem Garnet Overseas Bowling Ball Roto Grip ExtremeTrax Pearl Reactive May 2023

Where the Roto Grip Defiant LRG 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 0.047Radical Vexed Variant Asymmetric Core, RG 2.490, diff 0.045Radical Modified Intel Symmetric Core, RG 2.483, diff 0.032Motiv Affliction V2 Core, RG 2.480, diff 0.055900 Global Conduit A.I. Core, RG 2.590, diff 0.050Roto Grip GEM A.I. Core, RG 2.490, diff 0.057Hammer Obsession Tour Core, RG 2.469, diff 0.034Hammer Super Offset Core, RG 2.524, diff 0.053Hammer Gas Mask Core, RG 2.500, diff 0.058Ebonite 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 0.030Storm 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 0.051Storm C3 Centripetal Control Core, RG 2.490, diff 0.029Roto Grip Rondure MaxD Core, RG 2.500, diff 0.058Hammer 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 0.046Radical 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 Strobe A.I. Core, RG 2.510, diff 0.052Radical Guru Core, RG 2.503, diff 0.044Track I-CORE 3.0, RG 2.486, diff 0.056DV8 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 0.043Track Stealth Core, RG 2.482, diff 0.056Brunswick 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 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 High Rev Offset Core, RG 2.489, diff 0.053Hammer 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 0.022Ebonite Iron Fist V2 Core (pictured: Ebonite Spartan Pearl Bowling Ball)1Motiv Predator V2 Core (pictured: Motiv Jackal Onyx Bowling Ball)2Hammer Vindicator Core (pictured: Hammer Reckoning Bowling Ball)3Storm Element Max A.I. Core (pictured: Storm Ion Max Bowling Ball )4900 Global Blast A.I. Core (pictured: 900 Global Vengeance Bowling Ball)5Motiv Detonator Core (pictured: Motiv Steel Forge Bowling Ball)6Roto Grip Defiant LRG Core (pictured: Roto Grip Gem Crystal Overseas 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 Defiant LRG Core
Core Brand Shape RG Diff vs this core
Ebonite Spartan Pearl Bowling Ball1Ebonite Iron Fist V2 CorePictured: Ebonite Spartan Pearl
 Ebonite Asymmetric 2.473 0.053 RG +0.003 · Diff 0.000
Motiv Jackal Onyx Bowling Ball2Motiv Predator V2 CorePictured: Motiv Jackal Onyx
 Motiv Asymmetric 2.470 0.054 RG 0.000 · Diff +0.001
Hammer Reckoning Bowling Ball3Hammer Vindicator CorePictured: Hammer Reckoning
 Hammer Asymmetric 2.474 0.053 RG +0.004 · Diff 0.000
Storm Ion Max Bowling Ball 4Storm Element Max A.I. CorePictured: Storm Ion Max Bowling Ball 
 Storm Asymmetric 2.470 0.055 RG 0.000 · Diff +0.002
900 Global Vengeance Bowling Ball5900 Global Blast A.I. CorePictured: 900 Global Vengeance
 900 Global Symmetric 2.470 0.055 RG 0.000 · Diff +0.002
Motiv Steel Forge Bowling Ball6Motiv Detonator CorePictured: Motiv Steel Forge
 Motiv Symmetric 2.470 0.055 RG 0.000 · 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 Defiant LRG CoreNone of the 8 balls with the Roto Grip Defiant LRG Core are in stock at BowlersMart right now.Show 8 balls no longer available at BowlersMartMore bowling balls with the Roto Grip Defiant LRG CoreBallCoverFirst seenRoto Grip Magic Gem Bowling BallRoto Grip MicroTrax Hybrid ReactiveSeptember 2023Roto Grip Exotic Gem Bowling BallRoto Grip MicroTrax Pearl ReactiveOctober 2022Roto Grip Gem Bowling BallRoto Grip MicroTrax Solid ReactiveFebruary 2022Roto Grip Gem Hybrid Overseas Bowling BallRoto Grip Hyper Response Hybrid ReactiveJune 2023Roto Grip Purple Gem Overseas Bowling BallRoto Grip MicroTrax Solid ReactiveJune 2023Roto Grip Gem Pearl Overseas Bowling BallRoto Grip Hyper Response Pearl ReactiveDecember 2022Roto Grip Gem Crystal Overseas Bowling BallRoto Grip Hyper X Hybrid ReactiveNovember 2024Roto Grip Gem Garnet Overseas Bowling BallRoto Grip ExtremeTrax Pearl ReactiveMay 2023Where the Roto Grip Defiant LRG sitsEach dot is a core in balls we stock. Cores close together roll alike; the cover and layout decide the rest.All coresSymmetricAsymmetricRoto Grip onlyAny brand900 GlobalBrunswickColumbia 300DV8EboniteEpicHammerKR StrikeforceMotivRadicalRoto GripSWAGStormTrack+−ResetZoom to this coreDV8 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 Cor

From Roto Grip’s description

Questions bowlers ask

What is the RG of the Roto Grip Defiant LRG Core?

At 15 lb the Roto Grip Defiant LRG Core has an RG of 2.470. It ranges from 2.470 to 2.590 across the listed weights.

What is the 14 lb RG of the Roto Grip Defiant LRG Core?

At 14 lb the RG is 2.500.

What is the differential of the Roto Grip Defiant LRG Core?

At 15 lb the differential is 0.053. The mass bias is 0.016.

Which bowling balls use the Roto Grip Defiant LRG Core?

Roto Grip Magic Gem Bowling Ball, Roto Grip Exotic Gem Bowling Ball, Roto Grip Gem Bowling Ball, Roto Grip Gem Hybrid Overseas Bowling Ball, Roto Grip Purple Gem Overseas Bowling Ball. 0 are in stock now.

Can I still buy a ball with the Roto Grip Defiant LRG Core?

Balls with this core are currently unavailable at BowlersMart. Closest in-stock alternatives by RG and differential include Ebonite Spartan Bowling Ball, Motiv Jackal Ghost V2 Bowling Ball, Hammer Reckoning Bowling Ball, Motiv Forge Fuel Bowling Ball, 900 Global Vengeance Returns Bowling Ball, Storm Ion Max Pearl Bowling Ball.

How do the Roto Grip Defiant LRG Core specs change by weight?

At 16 lb: RG 2.470, differential 0.051, mass bias 0.016. At 12 lb: RG 2.590, differential 0.029, mass bias 0.008.

How does the Roto Grip Defiant LRG 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 shown on BowlersMart’s original Roto Grip Defiant LRG core page (2022), 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

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