Overview
The ARRMA Pinion Gear, 16T HD Mod1 Safe-D5 (ARA310963) is an essential replacement or spare component for RC car UK enthusiasts who demand reliability and performance. This tough steel pinion gear is engineered for the demands of extreme RC conditions, making it the perfect addition to your RC tool box whether you're running a brushless speed truck, stunt vehicle, or competition buggy. The 16T tooth count provides a proven gear ratio suited to a wide range of ARRMA vehicles across multiple scales, from 1/5 scale speed trucks to 1/8 scale buggies and everything in between.
This precision-manufactured pinion gear incorporates ARRMA's Safe-D design philosophy, which prioritises reliability and peace of mind during high-performance driving. The distinctive D-shaped bore matches your motor shaft profile perfectly, ensuring secure engagement and preventing drive loss or brake failure if the set-screw ever backs out during intense bashing sessions. Whether you're a competitive racer, a weekend basher, or building your first ready to run RC car UK setup, having quality spare pinion gears on hand is crucial for keeping your vehicle in action.
Built from strong, durable steel with precision manufacturing throughout, this pinion gear is designed to withstand the punishment of aggressive acceleration, high-speed runs, and rough terrain. The wide tooth profile ensures smooth operation across all driving conditions, whilst the threaded set-screw hole and included hardware provide secure, reliable installation every time.
Key Features
- Strong and durable steel construction — The pinion gear is manufactured from hardened steel that delivers long-lasting performance even in extreme RC conditions, resisting wear and maintaining precise tooth engagement over extended use and repeated high-stress driving sessions.
- Precision manufactured wide tooth profile — The wider tooth design ensures smooth operation and better load distribution during power transfer, reducing noise and vibration whilst extending gear lifespan compared to standard tooth profiles.
- Safe-D shaped bore design — The D-shaped hole matches your motor shaft profile perfectly, providing dual benefits: it prevents drive loss if the set-screw backs out, and it prevents brake function loss, giving you confidence during high-performance runs and aggressive driving.
- 5mm motor shaft diameter compatibility — This pinion gear is engineered to fit motor shafts with a 5mm diameter, which is the standard specification across most ARRMA brushless RC vehicles and many other compatible platforms.
- Precision manufactured threaded set-screw hole — The M4 x 4mm set-screw hole is precisely machined to provide a secure, repeatable fit that holds firmly in place whilst remaining easy to adjust or remove for maintenance and gear changes.
- E-clip retention system supplied — The included 3.2mm E-clip provides positive axial retention of the pinion gear on the motor shaft, working in conjunction with the set-screw to ensure the gear cannot slide or shift position during operation.
- 16-tooth configuration — The 16-tooth count is optimised for balanced performance across acceleration, top speed, and torque delivery, making it a versatile choice for stock and modified vehicles across the ARRMA range.
- Mod1 gear pitch standard — The Mod1 (Module 1) pitch specification ensures compatibility with the spur gears fitted to ARRMA transmissions, providing perfect mesh alignment and smooth power delivery without binding or slippage.
Technical Performance
This 16T Mod1 pinion gear represents a refined engineering solution for serious RC enthusiasts who understand that transmission components are critical to overall vehicle performance. The steel construction provides superior hardness and wear resistance compared to alternative materials, essential when dealing with the shock loads generated by brushless motors delivering peak torque on demand. The Mod1 pitch specification means this gear meshes perfectly with standard ARRMA spur gears, maintaining the precise tooth engagement required for efficient power transfer and smooth acceleration characteristics. The Safe-D bore design is particularly significant in high-performance applications where aggressive driving or racing puts extreme stress on drivetrain components. By eliminating the risk of drive loss due to set-screw backup, ARRMA ensures that your vehicle maintains full throttle response and braking capability in competition or challenging terrain. The wide tooth profile reduces the stress concentration at individual tooth contact points, distributing loads more evenly across the gear face and enabling the component to handle the sustained high-torque conditions produced by modern brushless motors. The precision-manufactured threaded set-screw hole combined with the supplied M4 x 4mm hardware creates a secure mechanical interface that can be relied upon across repeated installation and removal cycles, essential for hobbyists who regularly maintain and upgrade their brushless RC trucks, buggies and speed machines. The included 3.2mm E-clip provides mechanical redundancy, ensuring that even if fastening is compromised, the gear remains retained on the motor shaft during operation.
What's in the Box
- 1 x 16T Mod1 Safe-D Pinion Gear (steel construction)
- 1 x Set Screw - M4 x 4mm
- 1 x E-Clip - 3.2mm
Frequently Asked Questions
- What ARRMA vehicles is the 16T Mod1 Safe-D5 pinion gear compatible with? — This pinion gear is listed as standard or optional parts for a comprehensive range of ARRMA vehicles including 1/5 scale models such as the KRATON 8S, OUTCAST 8S, and various versions with AVC and EXB platforms; 1/7 scale vehicles including BIG ROCK, FELONY, FIRETEAM, INFRACTION, LIMITLESS and MOJAVE models; and 1/8 scale vehicles such as KRATON 6S, NOTORIOUS 6S, OUTCAST 6S, TALION 6S and TYPHON 6S models. Check the comprehensive fitment list on the manufacturer's website to confirm compatibility with your specific model and variant.
- Why would I need a spare 16T pinion gear for my brushless RC truck or buggy? — Pinion gears experience constant high-stress engagement with the main spur gear, particularly in brushless vehicles where motors deliver significant torque on demand. Carrying spare pinion gears allows you to continue running your RC car UK setup at events or during weekend bash sessions without interruption. Worn or damaged gears compromise performance, reduce efficiency, and can lead to drivetrain damage. Having spares ensures you can quickly swap a worn component rather than abandoning your vehicle mid-session.
- What does the Safe-D bore design actually do and why does it matter? — The D-shaped bore matches your motor shaft profile instead of using a simple circular hole. This design prevents two critical failure modes: first, if the set-screw loosens and backs out, the D-shape ensures the gear and motor shaft remain mechanically locked, preventing loss of drive power; second, it maintains brake function even if fastening is compromised. This redundancy is particularly valuable during competitive racing or challenging terrain driving where sudden loss of drive or brakes could result in crash damage or lost competition performance.
- Is this pinion gear suitable for high-performance or modified RC vehicles? — Yes, the steel construction and precision wide tooth profile make this pinion gear suitable for both stock and modified vehicles. The hardened steel composition can handle the sustained high-torque outputs from brushless motors, making it appropriate for hot-rodded builds and competition applications. However, always verify fitment with your specific motor type and vehicle configuration, particularly if running upgraded or non-standard components.
- Will this 16T pinion gear fit my 5mm motor shaft? — Yes, the Safe-D5 designation confirms this gear is engineered for 5mm motor shafts, which is the standard across virtually all ARRMA brushless vehicles. The D-shaped bore is precisely machined to match 5mm motor shafts. Ensure your motor shaft is clean and free from burrs before installation, and use the supplied M4 x 4mm set-screw plus E-clip for secure retention.
- What is Mod1 gear pitch and why is it important for my RC car UK? — Mod1 (Module 1) is a standard gear pitch specification that defines the tooth size and spacing of the pinion gear. Using a Mod1 pinion with Mod1 spur gears ensures perfect mesh alignment, smooth power transfer, and efficient operation. Mismatched gear pitches result in binding, slipping, noise, and accelerated wear. This 16T Mod1 pinion gear is designed to work exclusively with Mod1 spur gears fitted to ARRMA transmissions.
- How do I install the set-screw and E-clip on my pinion gear? — Insert the M4 x 4mm set-screw through the threaded hole in the pinion gear and tighten it against the motor shaft using the appropriate hexagon key. Do not over-tighten; a firm but not extreme tension is appropriate. Once the set-screw is secure, install the 3.2mm E-clip into the groove on the motor shaft on the outboard side of the gear. The E-clip provides mechanical retention should the set-screw ever loosen. This dual-retention system ensures maximum security during high-performance driving.
- What is the difference between this 16T pinion and other tooth counts available? — Pinion gear tooth count directly affects gear ratio and vehicle performance characteristics. Smaller tooth counts (lower numbers) provide higher top speed but reduced acceleration torque; larger tooth counts (higher numbers) provide better acceleration and hill-climbing ability but lower top speed. The 16T configuration represents a balanced option suitable for mixed-use driving across various terrain types and speed ranges. If you find your vehicle too slow, consider a larger tooth count; if acceleration feels sluggish, try a smaller count.
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 Pinion Gear, 16T HD Mod1 Safe-D5 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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