Overview
The ARRMA 27T 0.8Mod Safe-D5 Pinion Gear is an essential replacement and upgrade component for RC enthusiasts across the UK who demand reliability and durability in their remote control vehicles. This tough steel pinion gear is engineered to deliver consistent performance in the most demanding RC conditions, making it the perfect part to carry in your RC tool box whether you are a seasoned basher, weekend racer, or dedicated competition driver. The 27-tooth configuration with 0.8 Module specification makes this pinion gear compatible with a wide range of ARRMA models and other RC cars UK that utilise standard motor shaft interfaces.
Built from high-quality steel and precision manufactured to exacting standards, this pinion gear combines durability with smooth operation. The innovative Safe-D5 design represents a significant advancement in RC drivetrain reliability, addressing one of the most common issues faced by RC car UK owners—the loss of drive or braking power when set-screws back out during intense driving sessions. Whether you are setting up a new electric RC vehicle or replacing a worn component on your existing model, this pinion gear delivers the performance and peace of mind that RC enthusiasts expect from ARRMA's trusted brand heritage.
The Safe-D5 specification refers to the specially shaped D-profile bore that matches your motor shaft profile precisely, ensuring secure engagement that maintains power delivery to your wheels even under the most extreme driving conditions. This design philosophy makes it an ideal upgrade for RC vehicle owners who want to eliminate drivetrain failures and keep their RC cars ready to run reliably, race after race.
Key Features
- Safe-D5 Bore Design — The distinctive D-shaped hole matches your 5mm motor shaft profile precisely, which means drive and brakes are not lost even if the set-screw backs out during intense driving, preventing the frustration of unexpected drivetrain failures mid-race or during a bashing session.
- Strong Steel Construction — Manufactured from durable steel rather than softer materials, this pinion gear delivers long-lasting performance in extreme RC conditions, maintaining its shape and tooth profile through countless hours of use without stripping or wearing prematurely.
- Precision Manufactured Wide Tooth Profile — The wide tooth design is engineered for smooth operation and reliable engagement with your spur gear, reducing noise, vibration and shock loads that can damage other drivetrain components, resulting in smoother acceleration and more responsive handling.
- 5mm Motor Shaft Compatibility — The Safe-D5 bore is specifically designed for 5mm diameter motor shafts, making this pinion gear suitable for a wide range of ARRMA models and popular brushless RC vehicles commonly used by RC enthusiasts across the UK.
- Precision Threaded Set-Screw Hole — The M4 x 4mm set-screw hole is precision manufactured with proper threading to ensure the fastener seats securely and maintains consistent clamping force throughout your driving sessions.
- E-Clip Retention System — The included 3.2mm E-clip provides additional security to prevent the pinion gear from sliding off the motor shaft, offering a redundant safety feature that keeps your drivetrain intact even if the set-screw were to fail completely.
Technical Performance
The ARRMA 27T 0.8Mod Safe-D5 Pinion Gear represents a refined approach to RC drivetrain engineering, combining materials science and precision manufacturing to solve real-world problems faced by RC car UK owners. The 0.8 Module specification defines the tooth size and spacing, ensuring proper meshing with compatible spur gears for smooth, efficient power delivery. At 27 teeth, this pinion provides a proven balance between acceleration and top-end speed across a wide range of RC vehicle applications, from electric RC buggies to monster trucks and crawlers. The steel construction provides superior durability compared to plastic alternatives, resisting the heat and stress generated during extended driving sessions. The Safe-D5 bore design is engineered with a D-profile that mates precisely with your motor shaft, eliminating the micro-slipping that can occur with traditional round bore designs when the set-screw loosens slightly. This engineering breakthrough ensures that power delivery remains constant and reliable, whether you are launching hard from a standstill, running at speed, or applying the brakes. The 5mm shaft diameter compatibility makes this pinion gear a direct fit for numerous ARRMA models and other popular ready to run RC vehicles available in the UK market. The precision-manufactured threaded hole for the M4 x 4mm set-screw ensures that fastener tension remains stable and consistent, preventing the gradual loosening that causes drivetrain failures. The inclusion of the 3.2mm E-clip provides a fail-safe retention system that works in conjunction with the set-screw, offering peace of mind during the most aggressive driving conditions.
What's in the Box
- 1 x 27T 0.8 Module Safe-D5 Pinion Gear
- 1 x M4 x 4mm Set Screw
- 1 x 3.2mm E-Clip
Frequently Asked Questions
- What does Safe-D5 mean and why is it better than standard pinion gears? — Safe-D5 refers to the D-shaped bore that matches a 5mm motor shaft profile. Unlike round bore designs, the D-profile prevents the pinion gear from slipping or rotating independently on the shaft if the set-screw becomes loose, ensuring drive and brakes are not lost during driving. This design is particularly valuable for RC car UK owners who experience frequent drivetrain failures with standard gears.
- Is this pinion gear compatible with my ARRMA RC model? — This pinion gear features a Safe-D5 bore designed for 5mm motor shafts and is suitable for numerous ARRMA models that use this standard shaft diameter. However, you should verify your specific model's motor shaft size and bore specification before purchasing. If you are unsure, our team at RC Model Shop can help you identify the correct pinion for your particular vehicle.
- What is the tooth count and why does it matter? — This pinion gear features 27 teeth with 0.8 Module specification. The tooth count affects the gear ratio between the pinion and spur gear, influencing your vehicle's acceleration and top speed. A 27T pinion provides a balanced setup suitable for various driving styles and conditions commonly encountered by RC enthusiasts.
- How does the Safe-D5 design prevent drivetrain failure? — The D-shaped bore matches your motor shaft profile, creating a mechanical key that prevents slipping if the set-screw loosens. This redundant safety system, combined with the included E-clip, ensures continuous power delivery to your wheels even under extreme driving stress.
- What tools do I need to install this pinion gear? — You will need a hex key or wrench to tighten the M4 x 4mm set-screw included in the box. The E-clip should be fitted to the motor shaft after the pinion gear is installed to provide additional retention security.
- Is this suitable for beginners? — Yes, this pinion gear is suitable for RC enthusiasts of all skill levels. It is a straightforward replacement or upgrade component that installs easily on any compatible motor shaft. The inclusion of fasteners and the E-clip makes the installation process straightforward for anyone performing basic RC maintenance.
- Can I use this pinion with other RC brands besides ARRMA? — This pinion gear is designed for motors with 5mm shaft diameters and Safe-D5 bore compatibility. Many RC vehicle manufacturers use similar shaft sizes, so it may be compatible with other brands, but you should verify shaft diameter and bore profile before purchasing to ensure proper fit.
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 27T 0.8Mod Safe-D5 Pinion Gear Z-ARA311010 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.
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