TRX3728A

Overview

The Traxxas Lower Chassis (Grey) TRX3728A is an essential replacement chassis component for owners of Traxxas Rustler and Bandit RC vehicles. Whether you're running a Rustler HD with XL-5 electronics or upgrading to the brushless Rustler HD BL-2S platform, this grey lower chassis provides the foundation you need to keep your RC car running at peak performance. As a dedicated spare part engineered by Traxxas, this chassis is designed with precision to ensure perfect compatibility with your existing drivetrain and electronics, making it an ideal choice for anyone looking to maintain, repair or upgrade their ready to run RC car in the UK.

Built for durability and designed to accommodate both flat and hump-style battery packs within its generous 166mm long battery compartment, this lower chassis delivers the flexibility modern RC enthusiasts demand. The grey finish provides a professional appearance while the robust construction ensures reliable performance whether you're bashing around the garden, competing at your local RC track, or enjoying weekend leisure drives. This is a genuine Traxxas component that integrates seamlessly with the #3725R ESC mounting plate, ensuring your electronic speed controller sits perfectly in place with no guesswork or modification required.

RC car owners know that having quality spare parts on hand is essential for keeping their vehicles in action. The Traxxas Lower Chassis (Grey) represents a smart investment in your RC hobby, whether you need it as a replacement following a crash, or you're building up a complete spare chassis set for quick repairs between sessions. Compatible with multiple Rustler and Bandit variants, this single part covers a wide range of popular Traxxas stadium truck platforms available across UK RC retailers and hobby shops.

Key Features

• 166mm Long Battery Compartment — The extended battery bay accommodates both flat and hump-style LiPo battery packs, giving you complete flexibility in your power setup without needing to modify the chassis or hunt for alternative battery configurations. This is particularly valuable if you like to experiment with different battery geometries for optimal weight distribution and handling characteristics.
• Dual Battery Style Compatibility — Whether you prefer the compact profile of flat batteries or the higher capacity density of hump-style packs, this chassis accepts both without any modifications or adapters. This versatility means you can optimise your RC car's balance and performance based on your specific driving style and venue conditions.
• #3725R ESC Mounting Plate Integration — Designed specifically to work with the Traxxas #3725R ESC mounting plate, this chassis ensures your electronic speed controller is positioned precisely for optimal wiring integration and thermal management. Using only the correct mounting plate guarantees proper fitment and eliminates potential electrical or mechanical issues that could arise from improvised setups.
• Professional Grey Finish — The grey colour scheme provides a clean, professional appearance that complements Traxxas liveries whilst remaining neutral enough to match custom paint schemes and decals. The durable finish resists fading and maintains its appearance through repeated outdoor use.
• Precision Traxxas Engineering — As an official Traxxas spare part, this lower chassis is manufactured to the same exacting standards as the original equipment, ensuring perfect geometry, stress distribution and durability throughout its service life. You're not buying a generic copy—you're investing in genuine Traxxas quality.
• Wide Model Compatibility — This single spare part is compatible with Rustler HD XL-5 variants in multiple colours (green, pink, orange and red), Rustler HD BL-2S brushless models, plus Bandit and Bandit VXL platforms, making it an excellent part to keep in your spares box for maximum coverage.

Technical Performance

The Traxxas Lower Chassis (Grey) TRX3728A is engineered from robust materials designed to withstand the rigorous demands of RC stadium truck racing and bashing. The 166mm battery compartment dimensions are precisely calculated to provide secure retention of both flat rectangular LiPo packs and the taller hump-style configurations that many UK RC enthusiasts prefer for their high-capacity setup. The chassis geometry is optimised for use with Traxxas's reliable XL-5 brushed electronic speed controller or the high-performance brushless BL-2S system, ensuring compatibility across the entire Rustler HD and Bandit range. The integration with the #3725R ESC mounting plate means your speed controller sits in a purpose-designed position that maximises airflow for cooling whilst keeping wiring runs short and organised. Whether you're running a 2S LiPo power system in your Rustler or pushing a 3S configuration, this chassis provides the structural foundation necessary to handle the torque and acceleration forces generated by Traxxas motors. The grey finish is applied to durable plastic that resists UV degradation and impact stress, maintaining its appearance and structural integrity through countless drives at your favourite UK RC venue.

What's in the Box

• Traxxas Lower Chassis (Grey) TRX3728A

What You Need to Complete

• #3725R ESC Mounting Plate (required for correct installation)
• Electronic Speed Controller (XL-5 brushed or BL-2S brushless, depending on your model variant)
• LiPo Battery Pack (flat or hump-style, 2S or 3S configuration compatible with your vehicle)
• Motor and motor mounting hardware (retained from your existing chassis or purchased separately)
• Suspension components, shock towers and associated hardware from your vehicle
• Servo, receiver and other electronic components from your existing build

Frequently Asked Questions

• Which Traxxas models does this lower chassis fit? — The Traxxas Lower Chassis (Grey) TRX3728A is compatible with Rustler HD 1/10 Electric XL-5 2WD stadium trucks in green, pink, orange and red variants, Rustler HD BL-2S 1/10 Electric 2WD brushless models in blue, orange, green and red, as well as Bandit and Bandit VXL platforms. This wide compatibility makes it an excellent spare part investment for owners with multiple Traxxas vehicles or anyone planning to upgrade between brushed and brushless systems using the same chassis platform.
• Can I use any battery style in this chassis? — Yes, the 166mm long battery compartment is specifically designed to fit both flat and hump-style LiPo battery packs, giving you complete freedom to choose the battery configuration that works best for your driving style and weight distribution preferences. This flexibility is a major advantage over chassis designs that only accommodate one battery style.
• What ESC mounting plate must I use? — You must use only the Traxxas #3725R ESC mounting plate with this chassis. Using alternative mounting solutions or trying to fit your ESC without the proper mounting plate can lead to electrical connectivity issues, inadequate cooling, or vibration-related failures that will compromise your RC car's performance and reliability.
• Is this a genuine Traxxas part or an aftermarket replica? — This is an official Traxxas replacement part, manufactured to the same precision standards as original equipment. Buying genuine Traxxas spares ensures perfect fitment, durability and warranty support from authorised UK RC retailers like RC Model Shop, rather than risking compatibility issues with inferior aftermarket copies.
• What happens if I need to replace my lower chassis? — Lower chassis damage from impacts or wear can compromise your vehicle's geometry and performance. Having a replacement chassis on hand means you can swap it out in minutes and get back to driving, rather than waiting for repairs or purchasing a complete new RC car. This is particularly valuable for owners who drive frequently at UK RC tracks or compete in organised events.
• Can I use this chassis with both XL-5 and BL-2S electronics? — Yes, this chassis is engineered to work with both the Traxxas XL-5 brushed electronic speed controller and the brushless BL-2S system, provided you use the #3725R ESC mounting plate. This compatibility makes it possible to upgrade your powertrain without needing a completely new chassis, saving you money whilst enjoying improved performance from brushless technology.
• What is the difference between flat and hump-style batteries? — Flat batteries are rectangular LiPo packs that sit low in the chassis, lowering the centre of gravity for improved handling. Hump-style batteries are taller packs that provide higher capacity in a more compact footprint. This chassis accommodates both styles, allowing you to optimise your specific setup based on whether you prioritise run time or handling characteristics.

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 Traxxas Lower Chassis (Grey) (166mm long battery compartment) (fits both flat and hump style battery packs) (use only with #3725R ESC mounting plate) TRX3728A 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.