- Brand: ARRMA
- Model Number: Z-ARA310996
- Part Type: Pinion Gear
- Tooth Count: 13 teeth
- Gear Pitch: 0.8 Module
- Bore Type: Safe-D5
- Bore Diameter: 5mm motor shaft
- Material: Steel
- Tooth Profile: Precision-manufactured wide tooth profile
- Included Set-Screw: M4 x 4mm
- Included Retention E-Clip: 3.2mm
- Set-Screw Hole: Precision-threaded
- Compatible Vehicle Scale: 1/10
- Compatible with: ARRMA Big Rock 4X4 3S BLX, ARRMA Kraton 4X4 4S V2 BLX and other ARRMA 4X4 models with 0.8 Mod transmission
- EAN Code: 5052127037945
Overview
The ARRMA 13T 0.8Mod Safe-D5 Pinion Gear is a precision-engineered replacement component designed for serious RC enthusiasts who demand reliability and performance from their brushless RC vehicles. This tough steel pinion gear is manufactured to exacting standards and represents the genuine ARRMA specification that comes equipped on high-performance models like the ARRMA Big Rock 4X4 3S BLX monster truck. Whether you're a dedicated basher pushing your ready to run RC truck to its limits, or a competitor looking to optimise your gear ratios, this pinion gear delivers the durability and precision you need to keep your RC car UK-legal and competition-ready.
Built for extreme RC conditions, this 13-tooth pinion gear is an essential spare part to carry in your RC tool box. The Safe-D5 design is a signature ARRMA innovation that prioritises reliability during high-speed runs and aggressive acceleration. With its precision-manufactured construction and proven compatibility with leading brushless motor systems, this pinion gear is the perfect upgrade or replacement component for 1/10 scale electric RC trucks and buggies running on 3S LiPo power systems.
ARRMA has engineered this pinion gear specifically for use with 5mm motor shafts commonly found on brushless motors used in 1/10 scale off-road RC vehicles. The intelligent design ensures smooth power delivery, consistent gear mesh, and minimal drivetrain wear, making it an investment in the longevity and performance of your RC setup. This is the component specification trusted by ARRMA on factory-built ready to run RC models.
Key Features
- Safe-D5 Bore Design — The D-shaped bore matches your motor shaft profile precisely, preventing drive loss and brake failure if the set-screw should back out during hard acceleration or impacts. This innovative safety feature keeps your RC car running smoothly even during extreme bashing conditions.
- Strong Steel Construction — Manufactured from tough, durable steel that withstands the enormous forces generated by brushless motors in 1/10 scale applications. Steel composition ensures long-lasting performance in extreme RC conditions and resists stripping under high torque.
- Precision Wide Tooth Profile — Every tooth is precision-manufactured with a wide profile that ensures smooth engagement with your spur gear, reducing noise, minimising vibration, and delivering consistent acceleration response across all driving conditions.
- 0.8 Module Specification — The 0.8 Mod pitch matches the ARRMA transmission system found on Big Rock and Kraton models, ensuring perfect gear mesh and optimal power transfer from your brushless motor to the drivetrain.
- 13 Teeth Configuration — This tooth count is carefully selected to deliver aggressive acceleration and strong low-end torque, making it ideal for off-road bashing on uneven terrain, rock crawling, and muddy courses where immediate throttle response is essential.
- 5mm Shaft Compatibility — Designed specifically for 5mm diameter motor shafts, which are standard on ARRMA brushless motors. The precision-manufactured bore ensures a secure fit without wobble or play.
- Threaded Set-Screw Hole — The hole is precision-threaded to accept the included M4 x 4mm set-screw, providing a secure mechanical lock that keeps the pinion gear firmly attached to your motor shaft during acceleration and braking.
- E-Clip Retention System — The supplied 3.2mm E-clip provides additional security by preventing the pinion gear from sliding along the motor shaft, ensuring that drive and braking forces are transmitted reliably every time you throttle.
Technical Performance
This pinion gear is engineered to perform in demanding applications where brushless motors generate tremendous power and torque. The ARRMA Big Rock 4X4 3S BLX, for example, produces incredible acceleration from its Spektrum Firma 3200Kv brushless motor paired with the BLX100 ESC, generating power that demands precision drivetrain components. With a 13-tooth count and 0.8 Module pitch, this pinion gear delivers a specific gear ratio optimised for the internal transmission geometry of ARRMA 4X4 platforms. The steel construction resists the high stresses imposed by 3S LiPo batteries (11.1V nominal) and the sustained power delivery of brushless systems. The precision-manufactured teeth ensure smooth gear mesh with the 57T spur gear commonly found in ARRMA transmissions, eliminating chatter and maximising efficiency. The Safe-D5 bore eliminates a critical failure point: a standard round bore can slip if the set-screw loosens, causing sudden loss of power and brake function. The D-shaped profile physically prevents rotation, guaranteeing that drive is maintained even if fastening tension diminishes. This design philosophy reflects ARRMA's commitment to durability and reliability in extreme RC conditions.
What's in the Box
- 1 x 13T 0.8 Module Safe-D5 Pinion Gear
- 1 x Set Screw M4 x 4mm
- 1 x E-Clip 3.2mm
Frequently Asked Questions
- What vehicles is the ARRMA 13T Safe-D5 pinion gear compatible with? — This gear is specified for ARRMA 1/10 scale 4X4 models including the Big Rock 4X4 3S BLX monster truck, Kraton 4X4 4S V2 BLX speed monster truck, and other vehicles with 5mm motor shafts and 0.8 Mod transmission systems. Always verify your vehicle's specifications before purchase.
- Why choose 13 teeth instead of other tooth counts? — The 13-tooth configuration delivers aggressive acceleration and strong low-end torque, making it ideal for off-road bashing, trail driving, and muddy terrain where immediate throttle response is critical. Other tooth counts like 14T or 26T offer different performance profiles; higher tooth counts favour top speed, while lower counts favour acceleration.
- What makes the Safe-D5 design better than standard pinion gears? — The D-shaped bore physically locks the pinion gear onto your motor shaft, preventing it from rotating even if the set-screw loosens. Standard round-bore pinions can slip, causing sudden loss of drive and brakes. This design eliminates that failure point, ensuring reliability during hard acceleration and impacts.
- Is this a genuine ARRMA component? — Yes, this is the official ARRMA specification (Z-ARA310996) that comes installed on factory-built ARRMA Big Rock and Kraton models. It is manufactured to ARRMA's exacting standards and recommended for replacement and maintenance.
- What is the difference between 0.8 Mod and other module pitches? — Module (Mod) refers to gear tooth pitch. ARRMA transmission systems use 0.8 Mod throughout, meaning teeth are spaced to match spur gears of the same specification. Mixing different modules will result in poor gear mesh, excessive wear, and drivetrain damage.
- Can I use this pinion gear on brushed motors? — This gear is designed for brushless systems with Safe-D motor shafts. Brushed ARRMA motors may use different specifications. Always verify your motor shaft diameter and bore type before purchasing replacement pinion gears.
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 13T 0.8Mod Safe-D5 Pinion Gear Z-ARA310996 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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