Fastrax 1/10 85mm Alloy Adjustable Shock Absorbers Pair FAST157

Overview

The Fastrax 1/10th 85mm Alloy Adjustable Shocks (Pair) represent an excellent entry point into the world of tunable suspension for RC car enthusiasts across the UK. These fully aluminium constructed shock absorbers deliver adjustability that typically costs far more, making them an outstanding choice for anyone looking to dial in their RC vehicle's handling characteristics without breaking the bank. Whether you're a weekend basher exploring your first suspension upgrades or an experienced racer fine-tuning your setup, these shocks provide the flexibility you need to optimize your RC car's performance across different track conditions and driving styles.

Built with quality aluminium construction throughout, these 85mm shocks are versatile enough to suit numerous 1/10th scale RC models in the UK market. The adjustable nature means you can experiment with spring rates and damping characteristics to suit your specific vehicle and driving preferences, making them an invaluable tuning tool for anyone serious about getting the best out of their RC setup. The compact yet sturdy design ensures reliability whilst maintaining a reasonable weight profile that won't negatively impact your vehicle's performance.

RC hobbyists know that suspension tuning can make the difference between an average-handling car and one that feels planted and responsive. These Fastrax shocks give you the ability to explore different setups without needing to purchase multiple shock sets, saving you money whilst expanding your technical knowledge of RC vehicle dynamics.

Key Features

• All-Aluminium Construction — Every component from the body to the spring cup is constructed from quality aluminium alloy, providing excellent durability and corrosion resistance whilst keeping weight to a minimum, which is crucial for maintaining responsive handling in your RC car.
• Alloy Threaded Body — The threaded aluminium body allows for precise adjustment of your shock setup, enabling you to fine-tune suspension geometry and ride height to match your track or terrain conditions perfectly.
• Alloy Spring Adjuster — This feature lets you easily modify spring preload and tension without removing the entire shock assembly, making mid-session adjustments quick and straightforward during testing or race day.
• Alloy Cap with Diaphragm — The diaphragm design helps manage oil volume changes during compression and extension, maintaining consistent damping performance and preventing oil leakage that can compromise shock function over time.
• Alloy Spring Cup — A dedicated aluminium spring cup ensures secure seating of your shock spring and distributes load evenly, contributing to consistent and predictable handling characteristics across varied driving conditions.
• Alloy Threaded Shock End — The threaded alloy end fitting allows versatile mounting options and secure attachment to your vehicle's suspension links, ensuring your shocks remain stable during hard cornering and aggressive driving.
• Accessory Pack Included — Each pair comes with standoffs and a foam compensator, giving you the mounting hardware and pressure management components needed to integrate these shocks into your suspension system effectively.
• Fully Adjustable Design — Unlike fixed shocks, these adjustable units let you experiment with different damping rates and spring combinations, helping you discover the optimal setup for your specific RC car model and driving style.

Technical Performance

The Fastrax 1/10th 85mm Alloy Adjustable Shocks represent a thoughtfully engineered approach to affordable suspension tuning for 1/10th scale RC cars. The 85mm length positions these shocks as a mid-range option, suitable for a wide variety of RC platforms commonly seen in the UK market, from crawlers to trail trucks and general off-road buggies. The all-aluminium construction throughout—including the body, spring adjuster, cap with diaphragm, spring cup, and threaded shock end—ensures lightweight performance without sacrificing structural integrity. This engineering approach is essential because suspension components bear significant forces during driving; the quality of materials directly impacts how well your RC car handles bumps, maintains traction, and responds to your control inputs. The diaphragm-equipped cap is a particularly important feature, as it compensates for oil volume changes during compression and extension cycles, maintaining consistent damping characteristics and preventing the oil leakage issues that can plague poorly designed shocks. The inclusion of a foam compensator and standoffs in the accessory pack demonstrates that Fastrax has considered the complete installation experience, ensuring you have everything needed to properly set up these shocks on your vehicle. For the price point, these shocks offer exceptional value and performance potential for RC enthusiasts looking to upgrade from basic fixed suspension or to build a more refined setup.

What's in the Box

• One pair of Fastrax 1/10th 85mm Alloy Adjustable Shocks
• Shock mounting standoffs
• Foam compensator
• Accessory pack with complete mounting hardware

What You Need to Complete

• Silicone Shock Oil (essential for proper damping and smooth operation)
• Shock oil in appropriate viscosity for your driving conditions and vehicle setup

Frequently Asked Questions

• Do I need to add oil to these shocks before using them? — Yes, these shocks require silicone shock oil to function properly. The oil provides the damping resistance that controls compression and extension, creating the suspension response you feel when driving. Without oil, the shocks will not perform as designed. You'll need to fill them with appropriate viscosity silicone shock oil and test for smooth operation before running your RC car.
• What viscosity of shock oil should I use? — The source doesn't specify an exact viscosity recommendation, but silicone shock oils typically range from thin (30 weight) for a softer, more compliant ride to thicker grades (50+ weight) for firmer damping. We recommend starting with a medium viscosity (40 weight) and adjusting based on how your vehicle handles different conditions.
• Will these shocks fit my RC car? — These are 1/10th scale 85mm shocks, designed for 1/10th scale RC vehicles. The 85mm length is a common size used on many popular platforms. However, you should verify that your specific vehicle model is compatible with 85mm shocks before purchasing. Check your vehicle's manual or contact us if you're unsure about fitment for your particular model.
• What is the difference between the 55mm, 75mm, and 85mm Fastrax shock options? — These represent different shock lengths for different vehicle types and mounting configurations. The 55mm shocks suit compact vehicles with tighter suspension geometry, the 75mm shocks work well on mid-sized platforms, and the 85mm shocks (this product) are ideal for larger vehicles or those requiring more suspension travel. The longer the shock, the more vertical travel your suspension can achieve, which can improve comfort over rough terrain and provide better ground clearance.
• Are these shocks suitable for beginners? — Yes, these shocks are excellent for beginners because they're affordable yet offer real adjustability that teaches you about suspension tuning. However, you should be comfortable filling the shocks with oil and making basic adjustments. If you're completely new to RC cars, we recommend pairing these with a beginner-friendly vehicle platform. The included accessory pack makes installation straightforward for anyone with basic mechanical aptitude.
• What mounting hardware comes with these shocks? — The accessory pack includes standoffs and a foam compensator. The standoffs provide proper spacing and alignment when mounting the shocks to your vehicle's suspension arms, whilst the foam compensator helps manage air volume changes inside the shock body during operation, which helps maintain consistent damping performance.
• How do I adjust the spring rate on these shocks? — The alloy spring adjuster allows you to modify spring preload and tension. You simply adjust the threaded collar on the top of the shock to increase or decrease the spring compression. This changes how stiff your suspension feels and how much load the spring carries, affecting your vehicle's ride height and handling characteristics.
• Can I use these shocks as an upgrade to my existing suspension? — Absolutely. Many RC enthusiasts upgrade from basic stock shocks to these adjustable Fastrax shocks to gain tuning capability. As long as your vehicle is 1/10th scale and designed for 85mm shocks, these represent a significant upgrade path that's affordable and effective.

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 FASTRAX 1/10TH 85mm ALLOY ADJUSTABLE SHOCKS (PAIR) FAST157 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.