Overview
The ARRMA 1/10 KRATON 4S BLX 4WD Brushless Speed Monster Truck represents the perfect balance of performance, durability and value for RC enthusiasts across the UK. Whether you're a seasoned basher looking for a reliable ready-to-run RC monster truck or someone just discovering the excitement of brushless RC vehicles, the KRATON 4S delivers impressive speed and uncompromising toughness in a package that won't break your budget. This fully assembled, ready-to-run brushless RC car comes factory-finished in striking red, complete with all electronics installed and calibrated, so you simply charge a battery and blast.
The KRATON 4S BLX stands uniquely positioned between agile 3S bashers and mighty 6S machines, offering next-level ARRMA performance without the extreme power demands or costs. The 4S brushless platform provides 55+ mph top speed capability in optimum conditions, delivering genuine speed thrills while maintaining the robust construction ARRMA is renowned for. With a menacing truck body, massive tyres, and a long wheelbase for stability, this 1/10 scale monster truck is prepared to handle furious blasting over dirt, through grass, and across paved surfaces with equal enthusiasm.
The latest V2 evolution represents a significant step forward in the 4S BLX platform. The strengthened, differential-compatible composite chassis now includes an aluminium-cased centre differential module that transforms traction across any surface condition. Combined with updated Spektrum waterproof electronics, enhanced dirt protection featuring wishbone guards and outdrive protectors, and a comprehensive package of proven ARRMA bashing features, the KRATON 4S BLX delivers premium ready-to-run performance that represents outstanding value for UK RC enthusiasts.
Key Features
- Aluminium-Cased Centre Differential — The new metal centre differential with oil-filled design provides the ultimate grip and traction across varied terrain, allowing superior handling and control during high-speed manoeuvres, whether you're bashing through rough dirt tracks or smooth paved surfaces.
- Updated Spektrum Brushless Power System — The Spektrum FIRMA 3668 2400Kv brushless motor combines with the Spektrum FIRMA 120A V2 Smart waterproof ESC to deliver smooth, consistent power with improved punch and driving feel, whilst the integrated cooling fan keeps temperatures down during extreme running sessions.
- Higher Torque Servo with Metal Gears — The Spektrum S662 digital servo offers 17kg/236oz-in of torque at 0.15 seconds per 60 degrees, featuring steel gears and an alloy case centre for improved heat dissipation, delivering sharper high-speed steering response and greater reliability during aggressive bashing.
- Comprehensive Dirt Protection — Wishbone dirt guards protect rear driveshafts, whilst deep side guards provide additional defence against dirt and debris intrusion, and a sealed centre differential design keeps contaminants away from critical components for extended service intervals and reliability.
- EXtreme Bash CVD Driveshafts — Front and rear constant velocity driveshafts with extreme bash composite sliders and steel coupling joints deliver unstoppable power whilst absorbing impacts, ensuring durability during hard crashes and intense bashing sessions.
- Long Wheelbase Stability — The 355mm wheelbase combined with 547mm overall length provides sure-footed handling and confident cornering at speed, whilst the wide 450mm front and rear track width creates an aggressive stance that enhances both appearance and stability.
- All-Metal Gear Differentials — Front and rear EXB all-metal gear differentials with proven steel main and input gears ensure reliability and efficient power distribution, handling the demands of 4S brushless performance without compromise.
- Twin Oil-Filled Shocks with Long Travel — Aluminium shock bodies with silicone O-rings provide supreme sealing, whilst long-travel suspension geometry with adjustable oil viscosity (550cSt standard) offers plush action and comfortable ride quality across rough terrain.
- Waterproof Electronics Package — Both the Spektrum FIRMA 120A V2 ESC and S662 servo feature waterproof and dustproof design, allowing confident running through water crossings and muddy conditions without electronics failure concerns.
- Dual Protocol Radio System — The Spektrum SLT3 2.4GHz transmitter with SR315 dual protocol receiver supports both SLT and DSMR protocols, offering flexibility and compatibility with multiple radio systems, whilst the 3-channel setup provides throttle, steering and auxiliary control.
- Modular Design for Easy Maintenance — The centre differential module and power components are designed for simple removal and access, allowing quick tuning adjustments and maintenance without requiring complete disassembly, keeping you blasting more and fiddling less.
- dBoots COPPERHEAD 2 LP Tyres — High-quality vented rubber tyres with aggressive chunky tread pattern provide solid grip across varied surfaces, with the low-profile design improving on-road handling whilst the medium-compound inserts maintain durability through extended running.
- Enhanced Chassis Protection — Front and rear skid plates, high shock towers, integrated servo saver with 25T spline fitment, and anodised aluminium centre brace with integrated rubber damper work together to protect vital components from impacts and absorb shock loads.
- IC5 Connectors with EC5 Compatibility — The Spektrum FIRMA 120A V2 ESC uses reliable IC5 connectors for safe, efficient power delivery, with EC5 compatibility providing connection flexibility for alternative battery packs.
- 4S LiPo Ready Platform — Compatible with 2S, 3S, or 4S LiPo batteries (minimum 5000mAh, 35C recommended), the KRATON 4S BLX scales efficiently across power levels, allowing you to choose battery configuration based on desired performance and runtime.
- Premium Factory Assembly — Every component comes fully assembled, trimmed, painted, and pre-calibrated by ARRMA, eliminating assembly time and ensuring consistent build quality straight from the box.
Technical Performance
The ARRMA KRATON 4S BLX represents a carefully engineered balance of performance, durability and usability. At 1/10 scale with dimensions of 547mm length, 450mm width, and 206mm height, the truck presents an imposing but manageable footprint suitable for both garden-scale running and larger bashing venues. The 4.2kg weight (without battery) contributes to realistic mass whilst remaining light enough for quick acceleration and responsive handling. Power delivery comes from the Spektrum FIRMA 3668 2400Kv brushless motor, a 4-pole construction design delivering smooth, consistent power across the RPM range. The motor features a beautifully etched aluminium can with integrated heatsink and cooling fan, ensuring temperature stability during extended running. The 5mm shaft and gold 4mm bullet connectors provide reliable mechanical and electrical connection, whilst the Safe-D5 E-Clip groove adds safety during operation. The Spektrum FIRMA 120A V2 Smart ESC represents a significant upgrade in the 4S platform, offering waterproof and dustproof design with 120A continuous current rating suitable for 2S, 3S, and 4S LiPo batteries. Intelligent features include low voltage cut-off and thermal overload protection, user-programmable punch, brake, BEC, reverse speed and motor timing settings, and integrated fan cooling. The ESC connects via reliable IC5 connectors (EC5 compatible) using high-quality 12awg wiring for efficient power delivery. The final gear ratio of 12.48 combines a 57T steel spur with 13T steel pinion, delivering a balance between acceleration and top speed across 4S power levels. The three differentials (front, centre and rear) utilise steel internal gears with specified viscosity oils (front and rear: 10,000cSt, centre: 500,000cSt), tuned for optimal traction across varied terrain. The centre differential represents the V2 evolution's major advancement, featuring sealed design and oil-filled construction for ultimate grip without maintenance complexity. The transmission utilises extreme bash CVD slider-type driveshafts front and rear with steel couplings, capable of absorbing impact loads during crashes. Suspension geometry features double wishbone design front and rear with turnbuckle adjustments for geometry tuning, combined with long-travel aluminium shock bodies filled with 550cSt silicone oil for plush action and consistent damping. The 17mm aluminium wheel hexes provide durable connection to 17mm wheel studs, with medium-compound dBoots COPPERHEAD 2 LP tyres (156mm diameter) glued to black multi-spoke wheels. Battery mounting accepts hardcase LiPo packs up to 156x51x48mm, with wire clip retention ensuring secure fitment during high-performance running. The composite chassis is moulded from durable material with captured hingepins providing geometric security, adjustable body mounts, and comprehensive wire routing for clean electronics integration.
What's in the Box
- 1 × ARRMA KRATON 4S V2 BLX 4WD 1/10 Scale Speed Monster Truck RTR (fully assembled and factory-finished in red)
- 1 × Spektrum FIRMA 3668 2400Kv brushless motor with heatsink and cooling fan
- 1 × Spektrum FIRMA 120A V2 Smart waterproof ESC with IC5 connectors
- 1 × Spektrum S662 metal-geared digital servo (17kg torque, 0.15s speed)
- 1 × Spektrum SLT3 2.4GHz 3-channel transmitter with improved grip and trigger feel
- 1 × Spektrum SR315 dual protocol receiver (SLT and DSMR compatible)
- 4 × AA batteries for transmitter
- 1 × Multi-tool and hex wrenches (2.0mm and 2.5mm)
- 1 × IC5 loop connector for use with single 3S or 4S battery pack
- 1 × Instruction manual
What You Need to Complete
- LiPo battery pack: either 1 × 4S hardcase LiPo, 1 × 3S hardcase LiPo, or 2 × 2S hardcase LiPo batteries (minimum 5000mAh, 35C continuous discharge rating, within dimensions 156 × 51 × 48mm)
- Compatible LiPo battery charger with balancing capability
- LiPo safe charging bag for secure battery storage and charging
Frequently Asked Questions
- What is the top speed of the ARRMA KRATON 4S BLX? — The KRATON 4S BLX achieves 55+ mph (88+ km/h) top speed in optimum driving conditions using a 4S LiPo battery. Actual speed will vary based on terrain, battery condition, motor break-in, and driving technique. Beginners typically experience lower speeds until they develop control skills.
- Is the KRATON 4S BLX suitable for beginners? — Yes, the KRATON 4S BLX is designed as a ready-to-run brushless RC monster truck with Skill Level 3 rating, making it suitable for enthusiasts with some RC experience. The Spektrum SLT3 transmitter features 50% and 75% throttle modes for beginners, allowing learners to develop control skills at reduced power before progressing to full performance. The vehicle's long wheelbase and wide track width provide excellent stability, whilst the comprehensive electronics package includes protective features like low voltage cut-off.
- What battery does the KRATON 4S BLX need? — The KRATON 4S BLX requires either a single 4S hardcase LiPo battery, a single 3S hardcase LiPo battery, or two 2S hardcase LiPo batteries connected in series. The minimum recommended specification is 5000mAh capacity with 35C continuous discharge rating. Battery dimensions must not exceed 156 × 51 × 48mm to fit within the chassis battery bay. 4S configuration provides maximum performance and speed, whilst 3S offers a good balance of power and runtime, and 2S parallel provides gentler performance suitable for learners.
- What is included in the box — do I need to build it? — The KRATON 4S BLX comes fully assembled, factory-finished, and ready-to-run (RTR). All electronics are installed and calibrated, the chassis is fully constructed, the body is painted and trimmed, and the tyres are mounted and glued. You simply need to charge a LiPo battery, insert AA batteries into the transmitter, and you can immediately start bashing. No building or soldering required.
- What is the difference between 4S and 6S brushless monster trucks? — The KRATON 4S BLX uses a 4S LiPo battery (14.8V nominal) and is designed for 4S compatible electronics including the Spektrum FIRMA 120A ESC and FIRMA 3668 motor. 6S machines use 6S LiPo batteries (22.2V nominal) with higher-rated ESCs and more powerful motors, delivering significantly greater speed and acceleration. The KRATON 4S offers an excellent middle ground between 3S bashers and 6S speed machines, providing genuine performance thrills with more manageable power levels and lower cost than 6S alternatives.
- Is the KRATON 4S BLX waterproof? — The Spektrum FIRMA 120A V2 ESC and S662 servo feature waterproof and dustproof design, allowing confident running through water crossings and wet conditions without electronics failure. However, for specific waterproof rating standards, please refer to the detailed instruction manuals supplied with the product, as waterproof ratings vary between components.
- What maintenance does the KRATON 4S BLX require? — Routine maintenance includes cleaning mud and debris from the chassis after muddy running, checking and replacing worn tyres, inspecting driveshaft joints for damage, and verifying servo and ESC connections remain tight. The modular centre differential module and main power components can be easily accessed for inspection or oil top-up without complete disassembly. The EXtreme Bash CVD driveshafts are designed to absorb impacts but should be checked after hard crashes.
- Can I use the KRATON 4S BLX indoors? — The KRATON 4S BLX is designed for outdoor off-road bashing on dirt, grass, and paved surfaces. Whilst technically capable of indoor running in large spaces, the 55+ mph top speed and high-torque brushless motor make it more suitable for outdoor venues with ample space. Always ensure you have adequate clearance and follow local regulations when operating RC vehicles.
- What radio system does the KRATON 4S BLX use? — The KRATON 4S BLX includes a Spektrum SLT3 2.4GHz 3-channel transmitter with fast response SLT protocol, paired with a Spektrum SR315 dual protocol receiver supporting both SLT and DSMR 2.4GHz protocols. The receiver is Spectrum SMART telemetry compatible when operating in DSMR mode with the Spektrum Dashboard app, allowing remote monitoring of vehicle telemetry data.
- What is the centre differential and why is it important? — The newly redesigned V2 centre differential is an aluminium-cased, oil-filled differential module that distributes engine torque between the front and rear axles with a 50/50 torque split. This provides enhanced traction and cornering performance across varied terrain, particularly on loose dirt and mixed surfaces. The centre differential allows more precise weight distribution and handling characteristics compared to traditional solid rear-driven designs.
Why Buy from RC Model Shop?
RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the ARRMA 1/10 KRATON 4S BLX 4WD Brushless Speed Monster Truck Red – C-ARA4408V2T3 today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.
