- Brand: ARRMA
- Part Number: Z-ARA311051
- EAN: 5052127038508
- Product Type: Spur Gear
- Tooth Count: 39T
- Module Pitch: 1.0
- Material: Steel
- Compatible Vehicles: ARRMA 1/5 Kraton 4X4 8S BLX EXB, ARRMA 1/5 Outcast 4X4 8S BLX EXB
- Motor Compatibility: Brushless (8S)
- Tune-Up Type: Transmission
- Manufacturing: Precision manufactured
- Included Quantity: 1 x Spur Gear
Overview
The ARRMA Spur Gear 39T (Z-ARA311051) is a precision-engineered transmission component designed specifically for high-performance brushless RC vehicles. Whether you're running an ARRMA Kraton or Outcast 8S monster truck, this replacement spur gear allows you to fine-tune your vehicle's gear ratio to match your driving style, terrain conditions, and performance requirements. For RC enthusiasts in the UK looking to optimise their brushless RC monster truck, this OEM-quality part delivers the performance adjustments you need without compromising reliability or durability.
This is an essential tune-up option for anyone serious about getting the most from their large-scale brushless RC truck. The 39-tooth configuration provides a specific gear ratio that works in harmony with the powerful 8S brushless motor systems found in modern ARRMA vehicles. By changing your spur gear, you can adjust acceleration and top speed characteristics, making this a must-have upgrade for competitive drivers, bashers, and tuners who demand control over their vehicle's performance envelope.
Built to withstand the immense forces generated by contemporary brushless motors, this spur gear is manufactured to the highest standards and represents the same quality and precision that ARRMA is recognised for worldwide. If you're looking for genuine ARRMA transmission parts for your ready to run RC truck, this is the component you need.
Key Features
- High-Quality Steel Construction — Manufactured from strong steel material engineered to deliver long-lasting durability across all driving conditions, whether you're bashng on rough terrain or running on smoother surfaces. Steel construction ensures the gear can handle the sustained power delivery from brushless motors without premature wear or tooth stripping.
- Precision Manufactured Tooth Configuration — Every tooth is manufactured to exacting tolerances using precision engineering techniques, ensuring smooth power transfer from your motor to the drivetrain. Consistent tooth geometry means reliable engagement with the pinion gear, eliminating drivetrain chatter and delivering predictable acceleration characteristics.
- Engineered for Brushless Motor Systems — Specifically designed to operate reliably when large-scale brushless motors are supplying power to your vehicle's drivetrain. The gear geometry has been optimised for the high RPM and high torque characteristics of modern brushless systems, ensuring it can handle sustained heavy-load operation without failure.
- 39-Tooth 1.0 Module Configuration — The 39-tooth count combined with 1.0 module pitch provides a specific gear ratio that has been proven effective across ARRMA's 8S vehicle lineup. This tooth count is widely recognised by the RC community as a balanced option for both speed-focused and acceleration-focused setups.
- Genuine OEM ARRMA Part — This is an authentic ARRMA transmission component, not an aftermarket substitute, ensuring perfect fitment and performance compatibility with your vehicle. Original equipment parts guarantee the exact specifications required for your Kraton or Outcast 8S.
Technical Performance
The ARRMA Spur Gear 39T represents the pinnacle of transmission component engineering for high-powered RC vehicles. Manufactured with a 1.0 module pitch and 39-tooth design, this gear is specifically calibrated to work seamlessly with the brushless motor systems found in ARRMA's 1/5 scale 8S vehicles. The precision manufacturing process ensures that each tooth profile is identical, delivering consistent power transfer with minimal backlash and maximum efficiency. When paired with your Kraton or Outcast 8S brushless monster truck, this spur gear will provide smooth acceleration characteristics and reliable drivetrain performance, even under extreme racing or bashing conditions. The steel construction means the gear can repeatedly handle the enormous forces generated by 8S brushless motor systems without exhibiting the premature wear patterns sometimes seen in lower-quality alternatives. For UK-based RC enthusiasts running brushless 8S setups, this is the specification you need for trouble-free transmission operation. The gear is a critical wear component, and regular inspection or replacement after heavy use is recommended to maintain peak performance. Whether you're upgrading from a worn original or experimenting with different gear ratios to optimise your vehicle's handling, this 39-tooth variant offers proven performance across a wide range of driving conditions.
What's in the Box
- 1 x Spur Gear (39T, Mod1)
Frequently Asked Questions
- What is a spur gear and why would I need to replace it on my RC truck? — A spur gear is the main transmission component that transfers power from your brushless motor to the vehicle's drivetrain. Over time, through normal use, the teeth can become worn, chipped, or damaged, reducing performance and causing grinding sounds. Replacing it restores smooth operation and can also allow you to tune your vehicle's performance by selecting different tooth counts to adjust acceleration and top speed characteristics.
- Is this spur gear compatible with my ARRMA Kraton or Outcast? — Yes, the Z-ARA311051 is specifically designed for ARRMA 1/5 scale vehicles including the Kraton 4X4 8S BLX EXB and Outcast 4X4 8S BLX EXB models. Always check your vehicle's specification plate to confirm compatibility before ordering. This is a genuine ARRMA OEM part, ensuring perfect fitment.
- What's the difference between the 39T and other tooth count options? — Different spur gear tooth counts provide different gear ratios, which affect your vehicle's acceleration and top speed. A 39-tooth gear is a balanced setup that works well for most driving styles. Lower tooth counts (like 35T or 37T) will increase top speed but reduce acceleration, while higher tooth counts will improve acceleration but reduce top speed. The 39T represents a proven middle ground for general-purpose driving.
- How often should I replace my spur gear? — Frequency depends on how much you drive and how intensively. Regular bashers might replace their spur gear every few months of active use, whilst competitive racers might replace them more frequently. Inspect the gear regularly for chipped or worn teeth. If you notice grinding sounds, loss of power delivery, or visible damage, it's time for a replacement.
- Will this gear work with my brushless motor system? — Yes, this spur gear is specifically engineered to handle the high RPM and high torque output of large-scale brushless motors. The precision tooth configuration ensures smooth engagement and consistent performance even under the demanding conditions created by brushless power systems. It is not recommended for use with other motor types.
- Is this an original ARRMA part or an aftermarket substitute? — This is a genuine ARRMA original equipment manufacturer (OEM) part, not an aftermarket clone. The part number Z-ARA311051 is the official designation, and the component is manufactured to ARRMA's exact specifications. Original parts guarantee perfect compatibility and the performance standards you expect.
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 Spur Gear 39T Z-ARA311051 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.
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