- Product Type: Pinion Gear
- Manufacturer: ARRMA
- Model Number: ARA310971
- Tooth Count: 24T
- Gear Module: Mod1
- Gear Profile Type: Safe-D5
- Motor Shaft Bore Diameter: 5mm
- Hole Shape: D-shaped (Safe-D design)
- Material: Steel
- Tooth Profile: Wide tooth profile, precision manufactured
- Set-Screw Specification: M4 x 4mm
- Set-Screw Hole: Precision manufactured threaded
- E-Clip Size: 3.2mm
- Included Accessories: 1 x M4 x 4mm set screw, 1 x 3.2mm E-clip for motor shaft retention
- Compatible Vehicles: ARRMA 1/5 scale (KRATON 8S, OUTCAST 8S), ARRMA 1/7 scale (BIG ROCK 6S, FELONY 6S, FIRETEAM 6S, INFRACTION 6S, LIMITLESS 6S, MOJAVE 6S), ARRMA 1/8 scale (KRATON 6S, NOTORIOUS 6S, OUTCAST 6S, TALION 6S, TYPHON 6S)
Overview
The ARRMA Pinion Gear 24T HD Mod1 Safe-D5 is an essential replacement or upgrade component for serious RC enthusiasts running ARRMA vehicles across their extensive model range. This tough steel pinion gear is the perfect part to carry in your RC tool box, whether you're a competitive racer, weekend basher, or dedicated RC car UK hobbyist. The 24-tooth configuration offers an excellent balance of acceleration and top-end speed, making it suitable for a wide variety of ARRMA platforms from 1/5 scale speed trucks down to 1/8 scale buggies and stadium trucks. With precision engineering and ARRMA's proven design philosophy, this pinion gear delivers the reliability you expect from a manufacturer that has established itself as a leader in the brushless RC vehicle market.
What sets this pinion gear apart is the innovative Safe-D design, which features a distinctive D-shaped hole that matches your motor shaft profile perfectly. This clever engineering means that even if your set-screw backs out during an intense RC session, you won't lose drive and braking capability—a common problem that has frustrated RC pilots for years. The inclusion of a precision manufactured threaded set-screw hole, M4 x 4mm set screw, and 3.2mm E-clip ensures that you have everything needed for a secure, reliable installation that will withstand the extreme demands of high-performance RC driving. For anyone running an ARRMA brushless RC vehicle, this 24T pinion gear is an invaluable spare to have on hand.
Whether you're upgrading your gearing for different track conditions or simply replacing a worn component, this pinion gear represents the quality you've come to expect from ARRMA. The wide tooth profile is precision manufactured to ensure smooth, efficient power transfer from your brushless motor to the spur gear, whilst the strong steel construction guarantees long-lasting performance even in extreme RC conditions. This is genuine ARRMA parts quality—not an aftermarket alternative—making it the trusted choice for builders and racers who demand the best.
Key Features
- Safe-D Hole Design — The D-shaped hole matches your motor shaft profile so drive and brakes are not lost if the set-screw backs out, providing peace of mind during intense off-road sessions and ensuring you maintain full control even if fasteners loosen over time.
- Strong Steel Construction — Manufactured from durable steel for long-lasting performance in extreme RC conditions, this pinion gear is engineered to handle high-torque brushless motors and the punishment of serious RC driving.
- Precision Manufactured Wide Tooth Profile — The carefully engineered tooth geometry delivers smooth operation and efficient power transfer, reducing vibration and noise whilst maximising drivetrain longevity.
- 5mm Motor Shaft Compatibility — Designed specifically to suit 5mm motor shaft diameter, the industry-standard size used on ARRMA brushless motors across their entire vehicle range.
- Precision Threaded Set-Screw Hole — The M4 x 4mm set-screw hole is precision manufactured to ensure a secure, repeatable fit that won't strip or loosen prematurely.
- Complete Installation Kit Included — Every pinion gear comes with an M4 x 4mm set screw and 3.2mm E-clip for motor shaft retention, giving you everything needed for immediate installation.
- 24-Tooth Configuration — The 24T tooth count provides a versatile gearing option that balances acceleration and top-end speed across ARRMA's diverse model lineup.
- Mod1 Profile — The Mod1 modulus gear profile is the standard specification for ARRMA vehicles, ensuring perfect meshing with your spur gear for quiet, efficient drivetrain operation.
Technical Performance
The ARRMA Pinion Gear 24T HD Mod1 Safe-D5 is engineered with precision to meet the demanding requirements of modern brushless RC vehicles. Built from strong steel rather than softer alternatives, this pinion gear resists the high-torque output from ARRMA's brushless motor systems whilst maintaining dimensional accuracy that ensures perfect mesh with your spur gear. The wide tooth profile is precision manufactured using advanced techniques that create smooth, quiet engagement, reducing drivetrain noise and minimising power loss during acceleration and deceleration. The 5mm bore diameter is the industry-standard size for ARRMA brushless motors, providing a secure fit that transfers maximum power to the drivetrain without slipping. The revolutionary Safe-D hole design uses a D-shaped profile that physically locks onto your motor shaft, preventing gear slip even if vibration causes your set-screw to loosen—a common failure point in high-performance RC driving where extreme acceleration and braking loads can stress fasteners to their limits. Every component has been precision manufactured to exacting tolerances, from the threaded M4 set-screw hole to the 3.2mm E-clip groove, ensuring reliable operation across ARRMA's extensive vehicle range including 1/5 scale speed trucks, 1/7 scale desert trucks and street bashers, and 1/8 scale buggies, stunt trucks, and stadium trucks. The Mod1 modulus specification ensures compatibility with OEM ARRMA spur gears, delivering the smooth power delivery that brushless RC racing demands.
What's in the Box
- 1 x Pinion Gear, 24T Mod1 Safe-D5
- 1 x Set Screw - M4 x 4mm
- 1 x E-Clip - 3.2mm
Vehicle Fitments
This 24T pinion gear is listed as a standard part across ARRMA's extensive vehicle range, including:
- 1/5 scale KRATON 8S models (including RTR, EXB, and EXB AVC variants)
- 1/5 scale OUTCAST 8S models (including AVC RTR, EXB, and EXB AVC variants)
- 1/7 scale BIG ROCK 6S 4X4 RTR Brushless Monster Truck
- 1/7 scale FELONY 6S AVC 4X4 RTR Brushless All-Road Street Bash
- 1/7 scale FIRETEAM 6S 4X4 RTR Brushless Buggy
- 1/7 scale INFRACTION 6S AVC 4X4 RTR Brushless All-Road Street Bash
- 1/7 scale LIMITLESS 6S 4X4 RTR and EXB Roller variants
- 1/7 scale MOJAVE 6S 4X4 RTR and EXB models
- 1/8 scale KRATON 6S 4X4 RTR and Roller variants (including V5 and V6 updates)
- 1/8 scale KRATON 6S EXB 4X4 RTR and EXB AVC models
- 1/8 scale NOTORIOUS 6S 4X4 RTR variants
- 1/8 scale OUTCAST 6S EXB AVC 4X4 RTR
- 1/8 scale TALION 6S EXB AVC 4X4 RTR
- 1/8 scale TYPHON 6S 4X4 RTR, TLR Tuned, and TLR Tuned AVC variants
If you're uncertain whether this 24T pinion gear is compatible with your specific ARRMA model, we recommend contacting RC Model Shop where our experienced team can confirm fitment for your vehicle.
Frequently Asked Questions
- Is the ARRMA 24T Pinion Gear Safe-D5 compatible with my ARRMA vehicle? — This pinion gear is listed as a standard part across ARRMA's extensive range from 1/5 scale speed trucks through to 1/8 scale buggies and stadium trucks. Check the vehicle fitments list above to confirm compatibility with your specific model, or contact RC Model Shop for assistance in identifying the correct pinion gear for your setup.
- What does the Safe-D design do and why does it matter? — The Safe-D hole features a distinctive D-shaped profile that physically locks onto your 5mm motor shaft, preventing gear slip even if vibration causes your M4 set-screw to back out. This is a significant safety feature because losing drive and braking capability mid-session could result in your vehicle becoming uncontrollable, potentially causing damage or safety issues.
- Can I use this pinion gear as a direct replacement? — Yes, this 24T Mod1 Safe-D5 pinion gear is a direct replacement part for ARRMA vehicles that originally came equipped with the same specification. It comes complete with the M4 x 4mm set-screw and 3.2mm E-clip needed for installation.
- What is Mod1 and why does it matter? — Mod1 refers to the modulus or pitch of the gear teeth. The Mod1 specification ensures perfect meshing between your pinion gear and spur gear, delivering smooth, quiet, efficient power transfer. Using the correct gear module is essential for reliable drivetrain operation and longevity.
- What size is the motor shaft bore? — The Safe-D5 pinion gear is designed for 5mm motor shaft diameter, which is the industry-standard size for ARRMA brushless motors. The D-shaped hole ensures a secure, slip-free fit.
- Is this pinion gear suitable for beginners? — Whilst this is a genuine OEM ARRMA part suitable for any ARRMA vehicle owner, pinion gear selection and installation typically requires basic mechanical knowledge. If you're new to RC maintenance, RC Model Shop's experienced team can provide guidance on proper installation and gearing selection for your specific driving style and track conditions.
- What is the difference between 24T and other tooth counts? — The 24T configuration represents a balance point in ARRMA's pinion gear range. Higher tooth counts (like 25T or 26T) provide stronger acceleration and lower top speed, making them suitable for tight, technical tracks or extreme terrain. Lower tooth counts (like 21T or 23T) deliver higher top speed with slightly softer acceleration, better for open circuits. The 24T is a versatile middle ground.
- How often should I replace my pinion gear? — Pinion gear lifespan depends on driving intensity, maintenance, and track conditions. Regular inspection for wear, cracks, or broken teeth is recommended. If you notice stripped teeth, grinding sounds, or vibration during operation, replacement is necessary. Carrying a spare 24T pinion gear in your RC tool box is sensible preventative maintenance practice.
- Will this improve my RC car's performance? — If you're replacing a worn or damaged pinion gear with an equivalent 24T Mod1 specification, you'll restore original performance. If you're changing from a different tooth count, gearing will adjust your acceleration and top-speed balance. RC Model Shop can advise on optimal gearing for your specific ARRMA model and driving conditions.
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, 24T 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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