RPM82252

Overview

Upgrade your HPI Baja 5B or 5T RC buggy with RPM's precision-engineered rear upper and lower A-arms in striking black. These are direct replacement parts designed to transform your off-road RC car's performance and durability without requiring any additional components. Whether you're a seasoned RC enthusiast in the UK or a dedicated weekend basher, RPM's rear A-arms represent a significant step up in suspension geometry and structural integrity compared to stock components.

RPM has invested considerable engineering effort into these rear arms, starting with the proven geometry of the original equipment but then implementing multiple advanced modifications to enhance both performance and longevity. The result is a suspension upgrade that addresses known weak points whilst maintaining complete compatibility with your existing Baja 5B or 5T setup. If you've experienced arm breakage or excessive wear with standard components, these RPM A-arms are engineered specifically to solve those problems and deliver the durability you need for serious off-road RC driving.

Available in a stylish black finish, these arms are also offered in a dyeable white version for those who want to personalise their RC car's appearance. Whether you prefer the sleek black aesthetic or want to dye your arms to match a custom colour scheme using standard Rit clothing dye and hot water, RPM gives you options to make your Baja 5 truly yours.

Key Features

• Forward-Shifted Shock Mount — The shock mount on the lower A-arm has been moved forward by a full quarter inch to eliminate the severe rubbing issue that would occur at the wheel-to-shock mount interface on stock arms, preventing the catastrophic breakage that plagues standard components. This forward movement also allows RPM to increase the material thickness around the shock mount itself, protecting the lower shock rod end from impact damage and ensuring it remains supported rather than becoming the lowest-hanging component in the assembly.
• Triple Hinge Pin Boss System — A third inner hinge pin boss has been incorporated at the inside hinge pin location of the lower A-arm, with structural ribs tied directly into all three hinge pin bosses. This clever engineering disperses impact energy and the rotational forces generated by engine torque across a much wider load-bearing area, dramatically improving strength and resistance to flex under extreme conditions.
• Advanced Corner Webbing — Similar structural corner webs to those found on RPM's acclaimed front A-arms have been designed into both the rear upper and lower A-arms. These ribs substantially improve strength and durability throughout the arm structure, helping the components withstand the punishment of aggressive off-road RC driving, high-speed jumps, and hard landings.
• Direct Replacement Design — These rear A-arms start with the basic geometry of the stock Baja 5B and 5T arms, meaning they fit directly into your existing setup with no additional brackets, adapters or modifications required. This makes installation straightforward and ensures perfect compatibility with all other Baja components.
• Dyeable White Option Available — In addition to the black version offered here, RPM also manufactures these rear arms in a dyeable white plastic that accepts standard Rit clothing dye with hot water, allowing you to customise your RC buggy to any colour scheme you prefer.
• Authentic Black Finish — The black plastic used for this version offers a stealth, professional appearance that complements both modern and classic RC buggy body designs whilst providing that factory-quality finish.

Technical Performance

These RPM rear A-arms represent a substantial engineering upgrade over standard HPI Baja 5B and 5T components. The design begins with the proven geometry of the original equipment but incorporates multiple performance enhancements throughout the structure. The repositioned shock mount addresses one of the most common failure points in Baja 5 suspension — the rubbing and subsequent breakage that occurs when the wheel contacts the stock shock mount during aggressive cornering and jumping. By moving this mount forward by 0.25 inches, RPM engineers have created clearance whilst simultaneously thickening the material in this critical zone. The triple hinge pin boss system with integrated structural ribs transforms how suspension loads are distributed through the arm, preventing the stress concentration that leads to cracks and fractures in standard components. The corner webbing design disperses both vertical impact loads and the lateral forces generated during high-torque acceleration, creating a much more robust suspension component suitable for serious RC bashing and racing. Material thickness and internal ribbing have been optimised throughout the assembly to maximise strength-to-weight ratio, ensuring you gain durability without adding unnecessary mass that would compromise handling characteristics. These arms are manufactured to exacting tolerances using RPM's proven plastic moulding process, delivering consistency and reliability across every unit produced.

What's in the Box

• 1x Rear Upper A-arm (black)
• 1x Rear Lower A-arm (black)

Frequently Asked Questions

• Are RPM rear A-arms direct replacements for my HPI Baja 5B or 5T? — Yes, absolutely. RPM's rear A-arms are engineered to utilise the same basic geometry as the stock arms, meaning they require no additional parts, brackets, or modifications to install. They bolt directly onto your existing Baja 5B or 5T without any compatibility issues.
• What problems do these RPM arms solve that stock arms have? — The primary issue addressed is the shock mount rubbing against the wheel, which causes stock arms to break. RPM has moved the shock mount forward by a quarter inch to eliminate this rubbing whilst also increasing material around that critical zone. Additionally, the triple hinge pin boss system and corner webbing prevent the flex and stress concentration that leads to cracks in standard components, giving you significantly improved durability.
• Can I dye these black arms to a different colour? — These particular arms are the black version and are designed to be colour-stable. However, RPM also manufactures a dyeable white version that readily accepts standard Rit clothing dye in hot water, allowing complete customisation to any colour you prefer. If you want the dyeable option, check for the white version under the same part number variation.
• How much stronger are these arms compared to stock? — Whilst exact strength figures depend on testing conditions, the engineering improvements are substantial. The forward-moved shock mount eliminates a primary failure point entirely. The triple hinge pin boss system distributes loads across a much larger area than the two bosses on stock arms. The corner webbing prevents the flex that causes stress cracks. Collectively, these modifications result in arms that withstand far more aggressive driving before failure.
• Will these arms improve my Baja 5's handling? — The geometric design maintains stock suspension geometry to preserve handling characteristics, so any improvement is primarily in durability rather than handling. However, by eliminating the flex that occurs in stock arms, you'll experience more precise and consistent suspension response, particularly during aggressive driving and jumps.
• Are these suitable for racing or just casual bashing? — These arms are suitable for both applications. The upgraded construction makes them ideal for weekend bashing where durability is critical, but they're equally at home in competitive RC buggy racing where reliability and consistent performance are paramount.

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 HPI Baja 5B & 5T Rear Upper & Lower Arms Black RPM82252 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.