VehiclesArrma Kraton 8S EXB V2

Arrma Kraton 8S EXB V2

1/5 scale · monster truck · ARA5808V2T1

Top speed: 43mphstock gearing
Speed set: 57mphincluded in the box
Final drive: 18.51:1
Tire: 211mm

Open in Top Speedsourced

Arrma Kraton 8S EXB V2 — Photo: Horizon Hobby

Specifications

Last modified Sep 24, 2026

Spec	Value	Basis
Drivetrain
Pinion	23TStock	Stock
Spur	47TStock	Stock
Transmission & axle	9.06:1Stock	Stock
Spur ÷ pinion	2.043:1Calculated	Calculated
Final drive	18.51:1Stock	Stock
Speed gearing, in the box	30T / 47Tpinion / spurStock	Stock
Final drive, speed gearing	14.19:1Stock	Stock
Wheels & tires
Tire diameter	211mmStock	Stock
Rollout	35.8mm per motor turnCalculated	Calculated
Power
Motor	1100KVStock	Stock
Motor shaft	8 mmStock	Stock
Battery	Up to 8SLiPoStock	Stock
Performance
Theoretical top speed, stock gearing	43.5mph on 8SCalculated	Calculated
Theoretical top speed, speed gearing	56.7mph on 8SCalculated	Calculated
Motor speed	32,560rpm, no loadCalculated	Calculated
Vehicle
Part number	ARA5808V2T1
Scale	1/5
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. The top speed is kinematic: an ideal no-load RPM with no slip and no loss under load, so a real car is slower. Speed gearing is the taller set that ships in the box but is not fitted; swapping it in is the owner's job, and the car runs hotter on it.

Gearing parts

Pinion and spur parts for the Arrma Kraton 8S EXB V2: fitted, and optional gearing supplied in the box
Component	Teeth	Pitch	Bore	Part number
Fitted at the factory
Pinion	23T	Mod 1	8 mm	ARA311043 (opens in a new tab)
Spur	47T	Mod 1	Not applicable	ARA310920 (opens in a new tab)
In the box, not fitted
Speed pinion	30T	Mod 1	8 mm	ARA311050 (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 (8 mm on the stock motor). Gearing in the box is supplied, not fitted: the fitted set is what the figures and the calculators use. Linked part numbers go to the maker's or official distributor's page for that part.

How these numbers were settled

The EXB version of the 1/5 Kraton 8S, with a Spektrum Firma 5687 1100Kv motor (the BLX runs 1250Kv) and the Firma 160A Smart ESC V2 rated for 3S to 8S.

Horizon prints a 9.06 gear ratio, the same transmission and axle figure printed for the Kraton 8S BLX, and the standard-parts list shows the same drivetrain: 47T spur, 19T idler, 39T spiral ring and 12T input.
The exploded view, the parts tech pack and the interactive exploded view label the fitted pinion '23T STD 8mm' (ARA311043), so the stock total is 47/23 x 9.06 = 18.51.
The manual's kit overview lists a supplied 30T Safe D8 'Speed' pinion (ARA311050), which gives 47/30 x 9.06 = 14.19.
The standard-parts list names the dBoots Copperhead2 MT set (ARA550089), whose page prints an overall diameter of 8.31 in (211mm).

Documents

ManualInstruction manual (Horizon PDF) (opens in a new tab)Change the pinion/motor, p. 29
Exploded viewExploded view (Horizon PDF) (opens in a new tab)Motor, 23T pinion and 47T spur
Parts listParts tech pack with Mod1 pinion options (Horizon PDF) (opens in a new tab)Pinion options, p. 2

Sources

Every figure on this page traces to one of these. Where they disagreed, the note above says which was used and why.