VehiclesArrma Big Rock 223S BLX DSC
Arrma Big Rock 223S BLX DSC
1/10 scale · monster truck · ARA4312V4
- Top speed
- 52mphcalculated
- Final drive
- 10.15:1
- Tire
- 131mm
Specifications
Last modified
| Spec | Value | Basis |
|---|---|---|
| Drivetrain | ||
| Pinion | 16TStock | Stock |
| Spur | 57TStock | Stock |
| Transmission & axle | 2.85:1Derived | Derived |
| Spur ÷ pinion | 3.563:1Calculated | Calculated |
| Final drive | 10.15:1Stock | Stock |
| Wheels & tires | ||
| Tire diameter | 131mmStock | Stock |
| Rollout | 40.5mm per motor turnCalculated | Calculated |
| Power | ||
| Motor | 3100KVStock | Stock |
| Motor shaft | 5 mmStock | Stock |
| Battery | Up to 3SLiPoStock | Stock |
| Performance | ||
| Theoretical top speed | 52.0mph on 3SCalculated | Calculated |
| Motor speed | 34,410rpm, no loadCalculated | Calculated |
| Advertised top speed | 50mphMaker's claim | Maker's claim |
| Vehicle | ||
| Part number | ARA4312V4 | |
| Scale | 1/10 | |
| Class | Monster truck | |
Stock is as the vehicle ships. Calculated is worked from the stock figures on this page rather than stored beside them, so the two cannot drift apart. Derived is worked out from gear tooth counts the maker publishes rather than printed as a ratio; the notes below say how. The top speed is kinematic: an ideal no-load RPM with no slip and no loss under load, so a real car is slower. The maker advertises 50 mph, which is their own claim on their own conditions.
Gearing parts
| Component | Teeth | Pitch | Bore | Part number |
|---|---|---|---|---|
| Fitted at the factory | ||||
| Pinion | 16T | Mod 0.8 | 5 mm | ARA310999 (opens in a new tab) |
| Spur | 57T | Mod 0.8 | Not applicable | ARA311167 (opens in a new tab) |
Tooth counts are the ones in the specifications above. Pitch is given as metric module (Mod 1, Mod 0.8) or diametral pitch (32P, 48P). They are different standards and are not interchangeable, even where the numbers look close. Bore is the pinion’s hole, listed separately from the motor shaft (5 mm on the stock motor). Linked part numbers go to the maker's or official distributor's page for that part.
How these numbers were settled
The 223S successor to the Big Rock 3S BLX V3 crew cab, with a Spektrum Firma 3660 3100Kv motor and the Spektrum SLT 80A 2-in-1 ESC and receiver rated for 2S or 3S LiPo.
- Horizon's spec table prints a 10.15:1 final drive.
- The standard-parts list names a 16T pinion, the 57T centre diff spur, and 37T diff sets driven by 13T input gears, and 57/16 x 2.85 = 10.15 matches the printed total exactly.
- The stock tire is the dBoots Ragnarok MT (ARA-1383), whose page prints an overall diameter of 5.15 in (131mm).
- Stock gearing computes to about 52 mph at 3.7V per cell against Arrma's 50+ mph on 3S.
Documents
Sources
- ARA4312V4horizonhobby.com (opens in a new tab)
- searchhorizonhobby.com (opens in a new tab)
- ARA310956horizonhobby.com (opens in a new tab)
- ARA311153horizonhobby.com (opens in a new tab)
- ARA-1383horizonhobby.com (opens in a new tab)
- ARA310999horizonhobby.com (opens in a new tab)
- Manual (PDF)horizonhobby.com (opens in a new tab)
- Manual (PDF)horizonhobby.com (opens in a new tab)
- ARA311167horizonhobby.com (opens in a new tab)
- ARA311165horizonhobby.com (opens in a new tab)
- SPMX-1081spektrumrc.com (opens in a new tab)
- SPMX-1081horizonhobby.com (opens in a new tab)
Every figure on this page traces to one of these. Where they disagreed, the note above says which was used and why.