RPM Front A-Arms 4S V2 ARRMA Kraton Outcast Suspension Upgrade RPM81682

Overview

The RPM Front A-Arms for 4S V2 Arrma Kraton and Outcast (RPM81682) represent a significant suspension upgrade for serious RC enthusiasts looking to maximise durability and handling performance on their brushless RC monster trucks and stunt trucks. Whether you're bashing through challenging terrain, competing in off-road events, or simply pushing your RC car UK to its limits, these engineered front A-arms deliver the strength, precision and adjustability that separates a stock setup from a competition-ready machine. RPM has engineered these suspension components from the ground up to address the real-world demands placed on ready to run RC vehicles during intense driving sessions.

Designed primarily for strength and durability, these front A-arms incorporate several intelligent engineering features that go beyond simply making a thicker part. The designers at RPM recognised that a quality upgrade isn't just about raw material thickness—it's about intelligent design, material science, and understanding how suspension geometry affects overall vehicle performance. These A-arms are specifically tailored for the 4S V2 versions of the ARRMA Kraton 4X4 4S V2 BLX Speed Monster Truck and the ARRMA 1/10 OUTCAST 4X4 4S V2 BLX Stunt Truck, making them essential replacements for drivers who demand reliability from their brushless RC setup.

If you're running either of these high-performance 4S BLX vehicles and experiencing chassis flex, steering inconsistency, or simply want to build a more durable platform for aggressive driving, these front A-arms will transform your suspension's responsiveness and longevity. The pair comes ready to install as a complete front suspension upgrade, replacing the stock ARRMA component ARA330711 with engineering-grade durability that will take a pounding and keep performing.

Key Features

• Nearly 25% Thicker Construction — The RPM front A-arms are engineered to be almost 25% thicker than OEM stock A-arms, providing dramatically improved impact resistance and structural rigidity that prevents bending under extreme driving conditions. This increased material density means your suspension maintains its geometry longer, especially during high-speed bashing and aggressive manoeuvres where flex in suspension components can cause handling issues and accelerate wear.
• Uniform Thickness Across Entire Length — Unlike some aftermarket parts that add thickness only in critical stress areas, RPM has engineered these A-arms with uniform thickness throughout their entire length, ensuring consistent strength distribution and predictable suspension behaviour. This design philosophy eliminates weak points and provides balanced durability across the entire component.
• Slop Elimination at Hinge Pins — The A-arms feature a precision design that dramatically reduces the amount of movement at the hinge pin connection points, effectively eliminating slop that would otherwise compromise suspension performance. Less slop directly translates to better steering response, more predictable handling, and more consistent maintenance of your camber, caster and toe angle settings—critical factors for precision driving and competitive racing.
• Secondary Shock Mount Hole for Adjustability — A second shock mount position is cleverly integrated further out on the arm, providing genuine suspension tuning flexibility without requiring different parts. This secondary mounting point allows you to configure a lower profile suspension setup that drops the ride height, lowering your vehicle's centre of gravity for improved cornering stability and better aerodynamic performance.
• Lower Ride Height Configuration — By utilising the outer shock mount hole position, you can lay the suspension down further, reducing overall ride height and achieving a lower centre of gravity. This suspension geometry adjustment improves cornering stability, reduces body roll during aggressive turning, and provides a more aggressive stance that many RC enthusiasts prefer for both performance and appearance.
• Engineering-Grade Nylon Construction — These A-arms are injection-moulded from RPM's ultra-tough blend of engineering-grade nylon compounds specifically formulated for RC racing and bashing applications. This material selection delivers an exceptional balance of rigidity, impact resistance and longevity that standard plastics simply cannot match, ensuring your suspension performs reliably in the most demanding conditions.
• Sold as Complete Front Pair — The package includes both left and right front A-arms, providing a complete front suspension upgrade in one purchase. This pair installation ensures symmetrical suspension geometry and eliminates any risk of mismatched components affecting handling balance.

Technical Performance

The RPM Front A-Arms for 4S V2 Arrma Kraton and Outcast are engineered for vehicles powered by 4S LiPo batteries and brushless motor systems, making them ideal for the high-torque environments found in modern RC monster trucks and stunt trucks. The construction methodology—injection moulding from engineering-grade nylon—creates components that are simultaneously rigid enough to maintain suspension geometry under extreme loads, yet flexible enough to absorb impact without catastrophic failure. The nearly 25% increase in material thickness compared to OEM components translates to substantially improved durability during aggressive bashing, jumps, and high-speed runs across rough terrain. The slop elimination at hinge pin connections is particularly critical in 4S brushless vehicles where the combination of high torque and responsive electronic throttle control can expose any weakness in suspension rigidity. By reducing this movement, the A-arms maintain more consistent suspension angles, which directly improves steering precision, tyre contact consistency, and overall handling predictability. The dual shock mount hole configuration provides genuine tuning capability without requiring part replacement—a sophisticated engineering solution that allows drivers to progressively lower ride height and adjust suspension rates through geometry rather than just spring rates. This flexibility is invaluable for drivers who want to optimise their setup for different terrain types, competition formats, or personal driving preferences. The uniform thickness across the entire component length ensures that stress distribution is balanced and predictable, preventing the weak-point failures that sometimes occur with designs that concentrate material only in specific areas. For UK RC enthusiasts running 4S brushless setups, whether with genuine ARRMA vehicles or custom builds, these A-arms represent the kind of quality upgrade that separates vehicles that need constant repairs from machines that simply perform reliably weekend after weekend.

What's in the Box

• RPM Front A-Arms for 4S V2 (pair - left and right)

Frequently Asked Questions

• Are these RPM Front A-Arms compatible with my ARRMA Kraton or Outcast? — These A-arms are specifically designed for the 4S V2 versions of the ARRMA Kraton 4X4 4S V2 BLX Speed Monster Truck and ARRMA 1/10 OUTCAST 4X4 4S V2 BLX Stunt Truck. They replace the stock ARRMA component number ARA330711. If you own the V1 (original 4S BLX) versions, you would need RPM part number 80822 instead. Always verify your vehicle generation before purchasing to ensure correct fitment.
• What is the difference between RPM A-arms and the stock ARRMA parts? — The RPM A-arms are nearly 25% thicker than stock ARRMA components, engineered with uniform thickness throughout their entire length for consistent durability. They feature slop elimination at the hinge pins for improved steering response and suspension geometry consistency. Additionally, they include a second shock mount hole position that allows you to configure a lower profile suspension setup. Stock ARRMA A-arms lack these durability enhancements and the secondary mounting flexibility, making them suitable only for casual driving rather than serious bashing or competition use.
• Will these A-arms improve my vehicle's handling? — Yes, significantly. By eliminating slop at the hinge pins, these A-arms provide more responsive steering and more consistent camber, caster and toe angle maintenance. This means your suspension geometry remains stable during aggressive manoeuvres, steering inputs are more directly translated to the wheels, and tyre contact remains more predictable. The secondary shock mount option also allows you to lower ride height for improved cornering stability. These performance improvements are particularly noticeable on rough terrain and during high-speed driving.
• How do I install these A-arms on my ARRMA vehicle? — Installation involves removing the stock A-arms by disconnecting them from the chassis and steering linkage, then installing the RPM replacements in their place. The installation procedure is straightforward for anyone with basic RC maintenance experience, though consulting the ARRMA assembly manual for your specific model is recommended. The parts connect using the same mounting points as the original components, making installation a direct bolt-on upgrade.
• Will these A-arms work with my current suspension shocks? — Yes, these A-arms are fully compatible with standard ARRMA suspension shocks. The secondary shock mount hole provides additional geometry options, but your existing shocks will continue to function correctly whether you use the standard or secondary mounting position. The choice of which hole to use depends on your desired ride height and suspension setup.
• Are these A-arms suitable for beginners? — These are an excellent upgrade for any driver, from beginners to advanced enthusiasts. Beginners will appreciate the improved steering response and durability, which reduces maintenance and repair frequency. The upgrade makes vehicles more reliable and easier to control, which actually improves the learning experience. Advanced drivers will appreciate the durability and the secondary tuning option for suspension geometry adjustment.
• What material are these A-arms made from? — RPM Front A-Arms are injection-moulded from engineering-grade nylon, a specialised plastic compound formulated specifically for RC racing and bashing applications. This material is significantly tougher than standard plastics, providing excellent impact resistance whilst maintaining enough flexibility to absorb shocks without catastrophic failure. Engineering-grade nylon is recognised throughout the RC hobby as the best material choice for high-stress suspension components.
• How much do these A-arms weigh? — The source material does not specify the exact weight of the A-arms. However, the increased material thickness means they are heavier than stock components, which actually provides a minor benefit by slightly lowering the vehicle's centre of gravity when installed. If weight is critical for your specific application, contact RC Model Shop directly for precise specifications.

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 RPM Front A-Arms for 4s V2 Arrma Kraton and Outcast RPM81682 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.