Team Associated 16mm Rear Spring 3.5 lb/in 1.5D 83mm Black AS81664

Overview

The Team Associated AS81664 16mm Rear Springs represent a significant advancement in RC suspension tuning for competitive 1/8 scale off-road racing. These 3.5 lb/in rear springs are engineered specifically for drivers who demand precise handling and superior traction on ungroomed and bumpy track surfaces. Whether you're competing at high-level events or pushing your RC buggy to its limits on challenging terrain, these springs deliver the compliance and consistency needed to maintain control when grip is at a premium. Part of Team Associated's latest 1.5D wire spring lineup, they represent the culmination of extensive development work focused on optimising performance where traditional springs struggle.

Team Associated recognised that whilst their existing 1.6mm wire springs performed excellently on high-grip, well-prepared track layouts, they couldn't provide the level of consistency required on lower-grip, ungroomed surfaces. The development team at Team Associated engineered these new 1.5D springs to address this challenge directly. By changing the wire diameter to 1.5mm, the spring's natural frequency and wire stress characteristics are fundamentally altered, allowing the suspension to compress and conform more readily to irregular track surfaces. This means your RC8B4.1 or RC8B4 will maintain better traction, offer improved bump handling, and deliver the predictable performance you need in demanding conditions. If you're serious about RC car racing in the UK and want to optimise your setup for lower-grip environments, these rear springs are an essential upgrade.

Available now at RC Model Shop, these genuine Team Associated springs are backed by our expert knowledge and commitment to quality. As an authorised retailer of Team Associated products, we ensure every spring meets the manufacturer's exacting standards for consistency and performance.

Key Features

• 1.5D Wire Diameter (1.50mm) — The reduced wire diameter from the standard 1.6mm changes the spring's natural frequency and stress distribution, allowing it to compress more easily and conform to low-grip track surfaces where traditional stiffer springs would struggle to maintain traction.
• 3.5 lb/in Spring Rate — This is a softer rate positioned in the lower-middle of the 1.5D range (3.40 to 3.75 lb/in), making it ideal for ungroomed conditions and providing excellent bump compliance without sacrificing control.
• 83mm Free Length — Specifically shortened from the previous 86mm standard, the 83mm free length is optimised to work perfectly with the lower shock towers on the latest RC8B4.1 chassis, ensuring proper suspension geometry and ride height.
• 10.25T Coil Count — This precise coil specification ensures the spring delivers consistent characteristics and works in harmony with Team Associated's suspension tuning range.
• Colour-Marked Ends (Black) — Both ends of the spring are colour-marked in black to distinguish the 1.5D wire springs from the 1.6D wire springs (which are marked on one end only), making identification quick and preventing accidental mixing during setup changes.
• Tightly Grouped Coil Variation — Each spring in this range features a tight 0.25 coil variation tolerance, allowing for precise fine-tuning of your suspension rate to match the exact grip levels of your local track or event conditions.
• Designed for Ungroomed Surfaces — Developed specifically for the challenging conditions encountered at events like DNC and Silver State, these springs excel where traction is inconsistent and track preparation is minimal.
• Compatible with 16mm Shock Absorbers — Engineered to fit standard 16mm diameter shock towers found on the RC8B4.1, RC8B4.1e, RC8B4, and other current and older Team Associated models.

Technical Performance

These rear springs represent a meaningful departure from conventional spring design philosophy in RC racing. The transition from 1.6mm to 1.5mm wire diameter may seem minor, but the engineering implications are substantial. A thinner wire exhibits different stress characteristics under load, which fundamentally alters how the spring responds to impacts and maintains compression under sustained pressure. This is precisely what Team Associated's engineering team exploited when designing the 1.5D lineup for the RC8B4.1. The softer 3.5 lb/in rate coupled with the 1.5mm wire diameter means the spring can more readily absorb the impacts and irregularities of low-grip, ungroomed track surfaces, translating to improved traction and more predictable handling characteristics. The 83mm free length has been carefully shortened from the previous 86mm standard to optimise the suspension package with the new lower shock towers introduced on the RC8B4.1, ensuring correct ride height and suspension geometry are maintained. The 10.25T coil specification provides consistency across the spring family, with each spring subject to tight quality control tolerances to ensure the 0.25 coil variation grouping is maintained. This level of precision manufacturing means you can confidently mix and match springs from the 1.5D range (spanning 3.40 to 3.75 lb/in) to dial in your exact setup preferences. For drivers competing with RC buggies in the UK, where track conditions can vary significantly between venues, having access to this finely-graded range of spring rates is invaluable for competitive consistency. The colour-marking system used on all 1.5D springs (marked on both ends) makes it impossible to accidentally confuse these softer springs with the stiffer 1.6D alternatives, a small but important quality-of-life feature that prevents setup mistakes during track days.

What's in the Box

• One Team Associated 16mm Rear Spring, 3.5 lb/in, 1.5D wire, 83mm free length, 10.25T coil count

Frequently Asked Questions

• Are these rear springs suitable for my RC8B4.1? — Yes, these AS81664 springs are specifically designed and recommended for the RC8B4.1 and RC8B4.1e models. The 83mm free length is optimised for the lower shock towers on these chassis, and they work with standard 16mm diameter shock absorbers found on these vehicles.
• What is the difference between 1.5D and 1.6D springs? — The primary difference is the wire diameter: 1.5D springs use 1.50mm diameter wire whilst 1.6D springs use 1.60mm wire. This difference fundamentally changes the spring's natural frequency and stress characteristics, making 1.5D springs more compliant and better suited to low-grip, ungroomed track surfaces. Additionally, 1.5D springs are colour-marked on both ends, whilst 1.6D springs are marked on only one end, making identification easy.
• Why would I choose a 3.5 lb/in spring over other rates in the 1.5D range? — The 3.5 lb/in rate sits in the lower-middle of the 1.5D range (which spans 3.40 to 3.75 lb/in) and offers a good balance of compliance and support. Choose this rate if your local track is quite low-grip and you need maximum traction and bump compliance. If your track has slightly more grip or you prefer a stiffer setup, consider the 3.75 lb/in option; if it's even lower grip, the 3.40 lb/in would be softer.
• Will these springs work with my older RC8B4 or other Associated models? — Yes, these 83mm rear springs with 16mm shock compatibility will fit the RC8B4 and other current and older Team Associated models that use 16mm shocks. However, always verify that your specific model uses 16mm diameter shock towers before purchasing.
• What does 10.25T coil count mean? — This refers to the total number of active coils in the spring. This specification is part of Team Associated's controlled spring design and ensures consistency across the product range. The tight 0.25 coil variation tolerance across all springs in this rate means each spring will perform virtually identically to its siblings.
• How do I know if I need these springs over standard springs? — If you race on ungroomed, low-grip track surfaces, or if you're struggling to maintain consistent traction on bumpy terrain with stiffer springs, upgrading to these 1.5D springs will likely improve your performance. The softer compliance allows better traction in low-grip conditions where standard springs would struggle to maintain contact with the track.
• Can I mix different rates from the 1.5D range? — Yes, absolutely. Many competitive drivers run different front and rear rates, or even different left and right rates, to fine-tune their setup. The tight 0.25 coil variation tolerance means you can confidently mix rates across the 3.40 to 3.75 lb/in range knowing each will perform as designed.

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 TEAM ASSOCIATED 16MM REAR SPRINGS BLACK 3.5LB/IN L83 10.25T 1.5D AS81664 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.