Overview
The ARRMA Sliding Motor Mount 4985 (25mm BCD) Z-ARA-2811 is an essential replacement and upgrade component for serious RC enthusiasts running ARRMA's high-performance 1/7 scale models in the UK. Whether you're a competitive racer, weekend basher, or dedicated hobbyist, this precision-engineered motor mount delivers the adjustability and reliability that modern brushless RC cars demand. Designed specifically for ARRMA's 1/7 LIMITLESS 8S AVC 4X4 RTR models, this sliding motor mount allows you to fine-tune your motor position for optimal performance, giving you control over pinion and spur gear mesh, acceleration characteristics, and overall drivetrain efficiency.
Motor mounts are critical to RC car performance and longevity. A quality sliding motor mount like this one enables you to adjust gear mesh precisely, which directly impacts acceleration, top speed, efficiency, and the lifespan of your drivetrain components. If you're upgrading from a factory setup or replacing a damaged mount, this ARRMA component ensures you're using genuine, factory-specification parts that are engineered to work seamlessly with your vehicle. The 25mm BCD (Bolt Circle Diameter) specification matches the exact motor mounting requirements of compatible ARRMA models, ensuring perfect fitment and reliability.
At RC Model Shop, we stock genuine ARRMA spares and upgrades for the UK's most popular ready-to-run RC cars. Whether you need replacement parts for maintenance, performance upgrades, or competition-grade tuning, we're here to help you keep your brushless RC car running at its best.
Key Features
- Precise Sliding Adjustment — This motor mount features a sliding mechanism that allows you to move your motor forward or backward along the chassis rails, giving you precise control over pinion and spur gear mesh spacing. Optimal gear mesh is absolutely critical for performance and drivetrain longevity, as poor mesh leads to noise, vibration, power loss, and accelerated wear on both your motor and transmission components.
- 25mm BCD Motor Mounting — The 25mm bolt circle diameter specification is engineered specifically for ARRMA's high-performance brushless motors, ensuring rock-solid mounting and perfect alignment. This ensures your motor runs true and transfers power efficiently to the gearbox without vibration or misalignment issues.
- Genuine ARRMA Component — As a factory ARRMA part, this sliding motor mount is engineered to exact specifications and tested for compatibility with your vehicle. Using genuine parts ensures reliability, proper fitment, and maintains the engineering integrity of your RC car's drivetrain system.
- LIMITLESS 8S Compatibility — Designed for the ARRMA 1/7 LIMITLESS 8S AVC 4X4 RTR in both Street Speed variants (Red/Black and White/Blue), this mount delivers the durability needed for high-powered 8S LiPo brushless performance. The 8S powertrain demands a rock-solid motor mount, and this component delivers the precision and strength required.
- Essential Spare and Upgrade — Whether you're replacing a worn component or fine-tuning your setup for competition, this motor mount is an essential part of any serious RC enthusiast's spares box. It's equally valuable for maintenance, performance optimisation, and racing preparation.
Technical Performance
The ARRMA Sliding Motor Mount 4985 represents quality engineering designed specifically for high-powered brushless RC vehicles. Built to accommodate the exacting demands of an 8S brushless electric drivetrain, this component plays a vital role in maintaining precise gear mesh and motor alignment, which are absolutely fundamental to performance and reliability. The sliding mechanism allows adjustment along the chassis rails, enabling you to dial in the perfect pinion-to-spur gear mesh, which directly influences acceleration response, top speed capability, efficiency, and the longevity of your entire drivetrain. In high-performance RC cars running brushless motors and 8S LiPo batteries—delivering hundreds of amps of power—even small variations in gear mesh can result in noticeable performance differences and accelerated wear. The 25mm BCD mounting interface is precisely engineered to accept ARRMA's range of compatible brushless motors, ensuring perfect motor alignment and vibration-free operation. For drivers of the ARRMA 1/7 LIMITLESS 8S AVC 4X4 RTR, whether running the Street Speed Red/Black or White/Blue variant, this mount provides the adjustability and precision required to optimise your setup for your preferred driving style, terrain, and racing conditions. Quality motor mounts are not just spare parts—they're essential tuning tools that every serious RC enthusiast should understand and be able to adjust.
What's in the Box
- ARRMA Sliding Motor Mount 4985 (25mm BCD)
Frequently Asked Questions
- What is a sliding motor mount and why do I need one? — A sliding motor mount allows you to adjust the position of your motor along the chassis rails, which changes the distance between your pinion gear and spur gear. This adjustment, called gear mesh, is absolutely critical to RC performance. Proper gear mesh ensures efficient power transfer, reduces drivetrain wear, and allows you to optimise acceleration and top speed. Most serious RC car owners adjust their motor mount regularly as part of chassis tuning.
- Which ARRMA models is this compatible with? — This sliding motor mount (Z-ARA-2811) is specifically designed for the ARRMA 1/7 LIMITLESS 8S AVC 4X4 RTR in both Street Speed variants: the Red/Black version and the White/Blue version. Before purchasing, verify your model number matches one of these two variants to ensure compatibility.
- What does 25mm BCD mean? — BCD stands for Bolt Circle Diameter. The 25mm specification refers to the diameter of the circle formed by the motor mounting bolt holes. This ensures your motor bolts align perfectly with the mount's bolt holes, guaranteeing secure, vibration-free mounting of your brushless motor.
- Is this suitable for beginners? — This is a replacement and upgrade component rather than a complete system. While beginners typically start with ready-to-run RC cars, understanding motor mounts and gear mesh adjustment is an important skill for anyone looking to progress in the hobby. If you already own an ARRMA LIMITLESS and want to learn about chassis tuning and motor mount adjustment, this component is an excellent introduction to performance optimisation.
- How often should I replace my motor mount? — Motor mounts are robust components designed to last through normal use. However, if you crash heavily, experience impact damage, or notice loose mounting or vibration, replacement may be needed. Regular inspection of your motor mount as part of maintenance ensures it remains in optimal condition, and having a spare in your spares box is prudent for any serious RC competitor.
- Can I use this on other ARRMA models? — This mount is engineered specifically for the ARRMA 1/7 LIMITLESS 8S AVC 4X4 RTR models listed above. Do not assume compatibility with other ARRMA models without confirming your specific model number, as different platforms use different motor mounting systems and may not accept a 25mm BCD motor mount.
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 ARRMA Sliding Motor Mount 4985 (25mm BCD) Z-ARA-2811 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.
We want to make sure your delivery goes smoothly, so here are some important details about our service:
- For orders above £120, we offer delivery to most mainland UK addresses. For orders under £120, we can still deliver to Northern Ireland and the outlying isles, as long as the item can be sent by Royal Mail, weighs less than 30kg, and fits within 61cm × 46cm × 46cm. Some highland and remote areas may carry an extra delivery charge as couriers often apply surcharges in these locations. If you live in one of these areas, feel free to contact us before ordering so we can confirm the delivery options and costs for you.
- Most of our products include delivery in the price. If your order is under £90, a small delivery fee will apply but do not worry this will always be clearly shown at checkout before you complete your purchase.
- Depending on what you choose at checkout, your order will usually be delivered either the next working day or within 2 working days. For next day delivery please place your order before 2:00pm. Orders are dispatched Monday to Friday only. Some items may take a little longer and if that is the case we will always show the expected delivery time on the product page.
- If your order includes items with different dispatch times we will normally wait and send everything together once all items are in stock. If one of the items is going to take a while we will give you the choice either wait for everything to arrive or let us send the available items now and deliver the rest later. It is up to you.
- We use trusted delivery partners to make sure your order gets to you safely and on time. We use DPD for next working day deliveries and Royal Mail for the 2 day option.
- As soon as your order is on its way we will send you a tracking number by email. If you provide your mobile number at checkout we will also send delivery updates straight to your phone so you can keep an eye on progress.
- If a product is marked as "Dispatched within 3 working days" delivery usually takes around 3 to 5 working days from when your order is placed.
- For customers in Inverness and other parts of the Scottish Highlands deliveries can take up to 2 working days even if you select next day delivery as couriers do not currently offer a guaranteed next day service to those areas.
