RPM ARRMA Kraton Notorious Outcast 6S Front A-Arms Left Red RPM81579

Overview

The RPM ARRMA Upper/Lower Left Front Arms in striking red are premium suspension components engineered for serious RC enthusiasts running 6S-powered ARRMA monster trucks and buggies. These A-arms represent a significant upgrade over standard equipment, offering enhanced durability, improved handling characteristics, and greater tunability for anyone looking to extract maximum performance from their brushless RC car or truck. Whether you're bashing at high speed across rough terrain or dialling in your setup for competitive racing, these suspension arms deliver the rigidity and reliability that RC fans across the UK demand from their equipment.

Designed specifically for the V5 and EXB editions of the ARRMA Kraton, Notorious, Talion, Fireteam and Outcast 6S models, these arms are also reverse compatible with earlier versions of these vehicles, making them an excellent choice for upgrading an existing RC monster truck or 6S RTR ready-to-run model. RPM has engineered these components using their proven nearly indestructible blend of engineering-grade nylons, ensuring they can handle the extreme forces generated by powerful brushless motors and high-output batteries. This is a suspension upgrade that serious RC bashers and racers trust to keep their vehicles performing at their best.

Each package contains one upper and one lower A-arm for the left front side of your vehicle, meaning you'll need both left and right packages to fully upgrade your suspension system. RC Model Shop stocks genuine RPM suspension components, so you're buying authentic parts with the engineering and quality assurance that comes from the manufacturer.

Key Features

• Significantly beefier construction — These A-arms are substantially thicker and more robust than RPM's original 6S version, with lower A-arm support beams 30% thicker and upper A-arms more than 22% thicker, delivering superior durability and reduced flex for more predictable handling.
• Reduced suspension flex — The increased thickness throughout the arm structure minimises unwanted flex, translating directly to more consistent suspension geometry, better steering response, and more predictable handling characteristics even during aggressive driving.
• Lower profile suspension option — The lower A-arm features an additional shock mount hole positioned further outboard, allowing you to run a lower suspension geometry that drops your ride height and lowers the centre of gravity for improved cornering speeds and more aggressive stance.
• Widened inner hinge pin mount — By eliminating caster spacers, RPM widened the upper A-arm's inner hinge point to create a more pronounced A-shape geometry, which actively stabilises the upper arm and improves both steering performance and suspension reliability.
• Engineering-grade nylon construction — Moulded from RPM's proven nearly indestructible blend of engineered plastics, these arms deliver the toughness required for harsh RC bashing conditions whilst maintaining the lightweight characteristics essential for performance.
• V5 and EXB compatibility — These arms are engineered as stock replacements for ARRMA's ARA330655 and ARA330656 components on the latest generation 6S models, with reverse compatibility for V4 and earlier versions when used with additional adaptor parts.
• Enhanced steering and suspension performance — The stabilised A-shape geometry, combined with reduced flex, creates a more responsive and predictable suspension system that translates to better traction control and cornering performance.

Technical Performance

RPM's approach to A-arm engineering focuses on the relationship between material thickness, structural stability, and performance. The 30% increase in lower A-arm support beam thickness and 22% increase in upper A-arm thickness represents a careful balance between weight and durability. These arms are moulded from engineering-grade nylon, a material choice that delivers exceptional toughness under the high lateral forces generated by 6S brushless RC trucks hitting jumps, landing hard, and powering through rough terrain. The elimination of caster spacers on the upper arm is not merely a cosmetic change; it allows RPM to widen the inner hinge pin mount area, creating a more A-shaped geometry that actively resists twisting and side-to-side movement. This structural improvement directly improves suspension response and longevity. The added shock mount hole on the lower A-arm provides genuine tuning flexibility for builders who want to experiment with ride height and weight distribution. By laying the shocks down at a lower angle, you achieve a lower centre of gravity—critical for high-speed cornering in 1/8 scale 6S monster trucks and speed buggies where weight distribution directly impacts grip and stability. For RC enthusiasts running 6S LiPo power in models like the ARRMA Kraton, Notorious, or Outcast, suspension durability becomes paramount as brushless motors deliver consistent, sustained power that can stress components over repeated use. These A-arms are engineered to handle that punishment reliably.

What's in the Box

• One upper front A-arm (left side)
• One lower front A-arm (left side)

What You Need to Complete

• One right-side A-arm package (RPM81578 or equivalent right-side kit) to complete a full front suspension upgrade
• For V4 and earlier ARRMA models: 1x ARRMA ARA713032 Shock Mount Pin and 1x ARRMA ARA330645 End Cap to ensure full compatibility

Frequently Asked Questions

• Are these A-arms compatible with my ARRMA Kraton 6S? — Yes, these RPM81579 arms are engineered as direct stock replacements for V5 and EXB editions of the ARRMA Kraton, Notorious, Talion, Fireteam and Outcast. They directly replace ARRMA part numbers 330655 (upper) and 330656 (lower). If you own a V4 or earlier model, these arms will also work but require one additional ARRMA ARA713032 Shock Mount Pin and one ARRMA ARA330645 End Cap.
• Will upgrading to RPM A-arms actually improve my RC truck's handling? — Yes, noticeably. The 22-30% thickness increase reduces suspension flex, which means your suspension geometry remains more consistent during acceleration, braking, and cornering. This translates to better predictability, improved steering response, and more consistent traction. The wider A-shape geometry on the upper arm actively stabilises the arm under load, further improving handling consistency.
• Can I use just these arms without replacing the right side? — Technically yes, but for balanced suspension performance, RPM recommends upgrading both left and right sides together. Using only the left side would create an asymmetrical suspension setup that could cause uneven handling characteristics.
• How much difference will the lower shock mount position make to my setup? — The additional outboard shock mount hole allows you to lower your vehicle's ride height and centre of gravity, which is particularly beneficial for high-speed driving. A lower centre of gravity improves cornering speeds and overall stability, especially noticeable in fast bashing and racing scenarios on flat terrain.
• Are these better than the original RPM 6S A-arms? — Yes, significantly. These newer arms feature 30% thicker lower support beams and 22% thicker upper arms compared to RPM's original 6S design, plus the additional benefits of the widened inner hinge mount and extra shock mounting position, making them a worthwhile upgrade even for existing RPM users.
• What's the difference between the upper and lower arms in this package? — This package contains both an upper and lower arm for the left front of your vehicle. The lower arm features the extra shock mount hole for tuning ride height, while the upper arm benefits from the widened inner hinge mount and A-shape geometry for improved steering and stability.

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 ARRMA UPPER/LOWER LEFT FR ARMS RED 6S KRAT/OUT/FIRETEAM RPM81579 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.