Overview

The RC4WD Bully II MOA Competition Crawler Kit (Z-K0056) is a purpose-built rock crawling machine engineered for serious competitors and enthusiasts who demand nothing less than competition-grade performance. This 1/10 scale electric RC crawler arrives as an unassembled kit, ready for builders who want to construct a genuine U.S.R.C.C.A. rules-compliant competition vehicle. Whether you're a seasoned RC crawler pilot looking to upgrade to a competition platform, or an ambitious hobbyist ready to take your skills to the next level, the Bully II MOA delivers the precision engineering and advanced features that separate winners from the rest on the rocks.

Built from the ground up with competition in mind, the Bully II MOA features a carbon fibre chassis paired with CNC-machined aluminium axles utilising the innovative Motor-on-Axle (MOA) design. This dual motor setup not only provides precise control over each wheel independently but also dramatically lowers the centre of gravity, improving stability and increasing run time compared to traditional single-motor configurations. The kit includes everything needed to build a fully competitive crawler, from titanium links and aluminium shocks to lightweight 2.2 beadlock wheels wrapped in Bully Advanced X2SS compound competition tyres. RC Model Shop stocks the RC4WD Bully II MOA as a UK-based authorised retailer, ensuring you receive genuine components with full support from our experienced RC team.

The estimated build time of 2–3 hours makes this an excellent weekend project for builders with intermediate to advanced skills. RC4WD has engineered every component with durability and performance in mind, utilising materials like titanium, carbon fibre, and billet aluminium throughout. This is not a ready-to-run RC car UK buyers grab off the shelf—this is a serious investment in a crawler that will perform when it counts, whether you're competing in sanctioned events or pushing your limits on challenging terrain.

Key Features

• CNC Machined Aluminium Axles with MOA Design — The Motor-on-Axle configuration places motors directly on the drive axles rather than in a traditional centralized location, which reduces your centre of gravity significantly and improves traction and control. This dual motor setup allows each axle to be controlled independently when paired with an appropriate electronic speed controller, giving you ultimate precision on the rocks.
• Carbon Fibre and Delrin Chassis — The chassis is constructed from high-quality carbon fibre, a material that provides exceptional strength-to-weight ratio. Combined with Delrin components, the chassis offers high clearance design to navigate obstacles whilst remaining lightweight, improving acceleration and overall performance.
• Steel Internal Heavy-Duty Gears and XVDs — The gearbox features hardened steel internal gears rated for extreme stress and abuse typical of competition crawling. XVD (Extreme Velocity Differential) components provide reliable power distribution even under the most demanding conditions, whilst clockable C-hubs allow for advanced tuning and adjustability.
• 90mm Internal-Spring Aluminium Shocks (Oil-Fillable) — The suspension utilises 90mm aluminium shock absorbers with internal springs, designed from the ground up to handle all terrain types and extreme flex. The oil-fillable design allows you to customise damping characteristics to suit your specific crawling style and terrain preferences.
• Titanium Links and Full Ball Bearings — Titanium links are used throughout the suspension linkage, providing superior strength whilst reducing unsprung weight. Every joint features full ball bearings for smooth articulation and reduced friction, translating to more responsive control and better wheel articulation.
• 2.2 Lightweight Competition Beadlock Wheels — The Rocker 2.2 beadlock wheels feature carbon fibre and Delrin construction, delivering extreme lightweight performance without sacrificing strength. At 25.3mm width with 15mm back spacing, these wheels are designed specifically for competition crawling, providing the exact geometry needed for optimal performance.
• Bully Advanced X2SS Compound Competition Tyres — These 2.2-class competition tyres feature a specialised advanced X2SS compound developed in collaboration with the RC4WD crawler team. The compound provides exceptional grip across multiple terrain types, having been extensively tested in varied conditions to ensure competition-ready performance straight out of the box.
• Carbon Fibre Battery Plate — The battery mounting solution is constructed from carbon fibre, reducing weight whilst maintaining the rigidity needed to keep your battery secure during aggressive manoeuvres.
• Easy-to-Paint Lexan Body Panels — The body panels are pre-made from Lexan material, ready for you to paint and personalise. This allows you to create a truly unique crawler that reflects your style whilst the Lexan provides durability and easy repair if needed.
• U.S.R.C.C.A. Rules-Compliant Design — Every aspect of the Bully II MOA has been engineered with the intention to meet U.S.R.C.C.A. competition rules, meaning you can build this kit knowing it will be legal and competitive in sanctioned events.
• Full Ball Bearings Throughout — Superior bearing quality is used extensively, reducing friction and improving responsiveness compared to lower-quality alternatives.
• Billet Aluminium Axle Cases — The axle cases are machined from billet aluminium, providing superior strength and precision compared to cast alternatives, and contributing to the overall durability expected of competition equipment.

Technical Performance

The RC4WD Bully II MOA Competition Crawler Kit delivers exceptional technical performance through careful engineering of every component. The dual Motor-on-Axle configuration is a game-changer for rock crawling, as it allows each motor to operate independently on its respective axle, dramatically improving traction control and reducing the centre of gravity compared to traditional single-motor setups. This translates to better weight distribution, improved stability when climbing steep obstacles, and increased run time from your battery due to more efficient power management. The axle ratio of 40.7:1 with 32P gearing and 14T pinion provides the torque multiplication necessary for climbing extreme terrain, whilst the 219.5mm hex width delivers a wide, stable stance. The suspension geometry features a 4-link design both front and rear, a proven competition configuration that provides excellent articulation and consistency across varied terrain. The 317mm wheelbase (12.5 inches) combined with 254mm width (10 inches) and 182mm height (7.2 inches) create a compact, nimble platform that excels in technical rock crawling where manoeuvrability is paramount. With a ground clearance of 92mm (3.6 inches) and a total weight of 1.99kg (4.38lb), the Bully II MOA achieves the light-yet-strong engineering philosophy that separates competition crawlers from casual builds. The kit accepts brushed motors in 35T, 45T, or 55T configurations, allowing you to tune power delivery to your preferences and terrain. Electronics compatibility includes the Outcry ESC options (with or without TurboBEC) for single-motor operation, or the specialist Rocker Dig II electronic controller for independent dual-motor management. The kit works with both 6-cell NiMH and LiPo battery packs, though LiPo is recommended for competitive use. The 90mm oil-fillable shocks can be precisely tuned with different oil viscosities to dial in suspension characteristics, making this a true competition-grade platform capable of performing at the highest levels of rock crawling competition.

What's in the Box

• 1x RC4WD Bully II MOA Competition Crawler Kit (includes all structural and mechanical components)

What You Need to Complete

Tools Required for Assembly:

• Hex drivers: 1.5mm, 2mm, 2.5mm
• Long nose pliers
• Side cutter pliers
• Thread locking adhesive (for metal-to-metal screws)
• Cross wrench or nut driver

Electronics Required to Complete:

• Brushed motor (35T, 45T or 55T)
• Electronic Speed Controller (ESC): Outcry (Z-E0008) or Outcry with TurboBEC (Z-E0007), or optional Rocker Dig II (Z-E0028) for independent motor control of the dual MOA setup
• Radio system: 2+ channels minimum (3-Channel Z-R0009 or 4-Channel XR4 Z-R0006 recommended)
• 1x Standard size servo (e.g., Z-E0035)
• Battery: 6-cell NiMH or LiPo (consult your ESC guidance for specific recommendations)
• Suitable charger for your chosen battery type

Suggested Compatibility and Upgrades

RC4WD provides numerous compatible parts and upgrade options for the Bully II platform, allowing you to customise and enhance your crawler as your skills develop:

• MOA Competition Crawler Chassis Set (Z-C0047)
• Bully 2 Competition Crawler Front Axle (Z-A0012) and Rear Axle (Z-A0084)
• Bully 2 Steering Link Kit (Z-S0952)
• RC4WD Superlift Superide 90mm Shock Absorbers (Z-D0015)
• M3/M4 Plastic Rod Ends – Long (Z-S1375), Short (Z-S1378), and Bent (Z-S0074)
• Heavy Duty Steel Black 3mm Con Washers (10) (Z-S0843)
• Rocker 2.2 Lightweight Competition Beadlock Wheels (Z-W0178)
• Bully 2.2 Competition Tyre (Z-T0134)
• Heavy Duty Metal Servo Arm – Futaba type (Black) (Z-S0182)
• RC4WD Medium Decal Sheet (Z-S1272)
• King Off-Road Dual Spring Shocks 90mm (Rear Only) (Z-D0061)
• Rock Krawler RRD Emulsion Dual Spring Shocks 90mm (Rear Only) (Z-D0052)
• Rocker Dig II (Electronic) for MOA Crawler (Z-E0028)
• Outcry Crawler ESC with TurboBEC (Z-E0007) or Dual Motor ESC with Fan & TurboBEC (Z-E0008)
• XR4 4-Channel 2.4GHz Radio (Z-R0006)
• RC4WD Brushed Boost Rebuildable 540 Motors: 35T (Z-E0045), 45T (Z-E0041), 55T (Z-E0044)

Frequently Asked Questions

• Is the RC4WD Bully II MOA suitable for beginners? — The Bully II MOA is best suited for builders with intermediate to advanced skills. Whilst the estimated 2–3 hour build time is reasonable, the complexity of the dual Motor-on-Axle system, precision CNC components, and requirement to source and install separate electronics means this is not a ready-to-run RC car for beginners. We recommend this kit for experienced RC enthusiasts or those with a strong mechanical background. First-time builders might prefer starting with a simpler kit before progressing to competition-grade crawlers.
• What battery does the RC4WD Bully II MOA need? — The kit is compatible with both 6-cell NiMH and LiPo battery packs. LiPo is generally recommended for competitive use due to superior power delivery and lighter weight. The exact capacity and specifications should be chosen based on your selected Electronic Speed Controller and motor combination. Consult your ESC manual for detailed battery recommendations, as different motor and gearing combinations benefit from different battery configurations.
• What is the Motor-on-Axle (MOA) design and why does it matter? — Instead of mounting motors centrally in the chassis like traditional crawlers, the MOA design places motors directly on the drive axles. This configuration dramatically lowers your centre of gravity, improving stability and reducing the chance of roll-overs on steep terrain. It also allows for independent motor control when paired with the Rocker Dig II electronic controller, letting you vary power to each axle for precise traction management. This is why the MOA design is specifically favoured in competition rock crawling.
• Can I use the Bully II MOA in U.S.R.C.C.A. competitions? — Yes, the Bully II MOA has been engineered with the specific intention to meet U.S.R.C.C.A. competition rules. Every component has been selected and designed to comply with sanctioned event regulations, meaning you can build this kit with confidence that it will be legal and competitive in official competitions.
• How long does it take to build this kit? — RC4WD estimates approximately 2–3 hours of build time. However, actual time may vary depending on your experience level and how meticulously you want to check pre-assembled components and apply thread lock to hardware. We recommend allowing extra time if this is your first assembly project.
• What electronics do I need to buy separately? — You will need to purchase: a brushed motor (35T, 45T, or 55T), an Electronic Speed Controller (ESC), a radio system with receiver (minimum 2 channels), a servo, and a battery with charger. The Outcry ESC options work well for single-motor operation, whilst the Rocker Dig II is specifically designed to independently control the dual MOA motors for maximum performance.
• Are the shocks oil-fillable? — Yes, the 90mm internal-spring aluminium shocks are designed to be oil-fillable, allowing you to customise suspension damping by using different oil viscosities. This advanced tuning capability is one of the features that makes the Bully II a true competition platform.
• What tools do I need to build this kit? — Essential tools include hex drivers (1.5mm, 2mm, 2.5mm), long nose pliers, side cutter pliers, thread locking adhesive, and a cross wrench or nut driver. Using quality hex drivers is particularly important to avoid stripping the precision screw heads on CNC components.
• How does the Bully II MOA compare to other competition crawlers? — The Bully II MOA sets itself apart through its dual Motor-on-Axle design, extensive use of premium materials (carbon fibre, titanium, billet aluminium), and competition-grade engineering. The combination of CNC-machined axles, full ball bearings, hardened steel gears, and U.S.R.C.C.A. compliance means this kit arrives ready to compete without requiring expensive upgrades. RC4WD has spent years testing and developing the Bully 2 platform to ensure it performs consistently at the highest competitive levels.
• Can I customise and upgrade the Bully II MOA? — Absolutely. RC4WD provides an extensive range of compatible parts and upgrades. You can upgrade shocks, wheels, tyres, axles, and numerous other components as your skills develop and your needs change. The modular design allows endless customisation for a unique build that matches your crawling style.

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 RC4WD and leading manufacturers like 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 RC4WD BULLY II MOA COMPETITION CRAWLER KIT Z-K0056 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.