Bowling ball core · Motiv
Motiv Sigma Core
Symmetric Motiv core
A symmetric core with early rev-up and medium flare, built for medium to heavy oil. 1 of the 5 balls with this core are in stock at BowlersMart.
- Symmetric
- RG 2.470
- Diff 0.047

Specs
RG AT 15 LB
2.470
Early rev-up
2% of the reactive and urethane balls we stock have a lower RG.
DIFFERENTIAL AT 15 LB
0.047
Medium flare
49% of the reactive and urethane balls we stock have a lower differential.
MASS BIAS AT 15 LB
None
Symmetric core
Symmetric cores have no mass bias marker to place when drilling.
| Weight | RG | DifferentialDiff | Mass biasMB |
|---|---|---|---|
| 16 lb | 2.480 | 0.041 | None |
| 15 lbUsed on this page | 2.470 | 0.047 | None |
| 14 lb | 2.500 | 0.044 | None |
| 13 lb | 2.560 | 0.034 | None |
| 12 lb | 2.630 | 0.024 | None |
Source: Motiv published specs, as shown on BowlersMart’s original Motiv Sigma 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.
Balls with the Motiv Sigma Core
1 of the 5 balls with the Motiv Sigma Core are in stock at BowlersMart. Same core, different covers: pick the cover for the lanes you bowl on.

Motiv Atomic Propulsion Pearl Reactive
Medium to heavy oil
Show 4 balls no longer available at BowlersMart
| Ball | Cover | First seen |
|---|---|---|
| Motiv VIP ExJ Sigma Limited Bowling Ball | Motiv Infusion Pearl Reactive | May 2023 |
| Motiv Forza SS Bowling Ball | Motiv Helix HFS (High Friction Solid) Solid Reactive | August 2017 |
| Motiv Rogue Blade Bowling Ball | Motiv Hexion SE (Strength Enhanced) Pearl Reactive | October 2018 |
| Motiv Rogue Assassin Bowling Ball | Motiv Coercion HFS (High Friction Solid) Reactive | July 2019 |
Where the Motiv Sigma sits
Each dot is a core in balls we stock. Cores close together roll alike; the cover and layout decide the rest.
Navy ring = a ball in your bag. Dashed ring = off this chart, or this same core.
Nearest cores, zoomed in
Navy ring = a ball in your bag. Dashed ring = off this chart, or this same core.
This core 1 Nearest cores Other cores
| Core | Brand | Shape | RG | Diff | vs this core |
|---|---|---|---|---|---|
|
|
Track | Asymmetric | 2.473 | 0.046 | RG +0.003 · Diff −0.001 |
|
|
Columbia 300 | Symmetric | 2.468 | 0.045 | RG −0.002 · Diff −0.002 |
|
|
Storm | Symmetric | 2.470 | 0.050 | RG 0.000 · Diff +0.003 |
|
|
Brunswick | Asymmetric | 2.478 | 0.048 | RG +0.008 · Diff +0.001 |
|
|
Hammer | Asymmetric | 2.470 | 0.050 | RG 0.000 · Diff +0.003 |
|
|
Ebonite | Symmetric | 2.480 | 0.048 | RG +0.010 · Diff +0.001 |
Matches use 15 lb RG and differential.
Drilling and tools
Turn on JavaScript to compare with your ball.Balls with the Motiv Sigma Core1 of the 5 balls with the Motiv Sigma Core are in stock at BowlersMart. Same core, different covers: pick the cover for the lanes you bowl on.
Questions bowlers ask
What is the RG of the Motiv Sigma Core?
At 15 lb the Motiv Sigma Core has an RG of 2.470. It ranges from 2.470 to 2.630 across the listed weights.
What is the 14 lb RG of the Motiv Sigma Core?
At 14 lb the RG is 2.500.
What is the differential of the Motiv Sigma Core?
At 15 lb the differential is 0.047. This is a symmetric core, so mass bias is not applicable.
Which bowling balls use the Motiv Sigma Core?
Motiv Sigma Tour Pearl Bowling Ball, Motiv VIP ExJ Sigma Limited Bowling Ball, Motiv Forza SS Bowling Ball, Motiv Rogue Blade Bowling Ball, Motiv Rogue Assassin Bowling Ball. 1 are in stock now.
How do the Motiv Sigma Core specs change by weight?
At 16 lb: RG 2.480, differential 0.041. At 12 lb: RG 2.630, differential 0.024.
How does the Motiv Sigma 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. Motiv published specs, as shown on BowlersMart’s original Motiv Sigma 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.


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