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Ebonite Spartan specs
The Ebonite Spartan is a solid reactive ball with the Iron Fist V2 core. Here are its published specs, how they compare with the other current balls in our table, and what the numbers mean on the lane.
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| Coverstock | HK22C² - Optimize Solid |
|---|---|
| Cover type | Solid reactive |
| Core (weight block) | Iron Fist V2 |
| Core type | Not stated |
| RG | 2.473 |
| Differential | 0.053 |
| Mass bias / intermediate diff. | 0.019 |
| Factory finish | 500, 1500 Siaair Micro Pad |
| Maker's category | Pro Performance |
| Color | Purple / Blue / Dark Blue |
| Weights | 16-12 Pounds |
| Release date (maker) | January 15, 2026 |
| USBC approved | 6 January 2026 |
Numbers as Ebonite publishes them, checked 21 October 2026. Published for a 15-pound ball. Drilling changes how a ball behaves, so a pro shop's layout matters as much as these numbers.
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What the numbers mean
RG 2.473. That is lower than 82% of the 134 current reactive and urethane balls in our table, so it sits on the low side. Storm says "a low RG ball will rev up quickly and roll smoothly."
Differential 0.053. Higher than 74% of the balls in our table. Storm says "a high differential ball will create a sharper angle of entry into the pins."
Solid reactive cover. Storm says solid covers are "particularly effective on fresh oil patterns," and bowling.com calls them best on heavier oil.
USBC allows an RG from 2.447 to 2.813 inches and a differential of at most 0.060 inches (Equipment Specifications Manual, March 2026). Our ball spec table lists every current ball we track, and who makes bowling balls covers which company owns Ebonite.
Balls with similar numbers
Same cover type, closest RG and differential in our table:
- Hammer Reckoning: RG 2.474, differential 0.053
- Track Synthesis: RG 2.480, differential 0.053
- Motiv Jackal Onyx: RG 2.470, differential 0.054
- Storm Equinox Solid: RG 2.470, differential 0.054
Sources: Ebonite product page; Storm, "Inside The Bowling Ball"; Storm, "The Coverstock"; bowling.com coverstock FAQ; USBC Approved Ball List (20 October 2026); USBC Equipment Specifications Manual.