RcThjia 5-Piece 64P Aluminum Pinion Gear Set 21T-25T for 1/10 RC Cars – 3.175mm Shaft, Includes M4 Screws and Hex Key

This 5-piece pinion gear set from RcThjia covers the most common tooth counts for tuning 1/10 scale RC cars: 21T, 22T, 23T, 24T, and 25T. Each gear has a 64P metric pitch and a 3.175mm bore, fitting standard 1/8-inch motor shafts. The set works with both brushed and brushless 540/550 motors and is compatible with brands like Traxxas, Axial, Arrma, HPI, Kyosho, Losi, and Tamiya TT01/TT02. M4 set screws and a hex wrench are included for quick gear changes.

Which gear ratios come in this set?

The set includes five pinions: 21-tooth, 22-tooth, 23-tooth, 24-tooth, and 25-tooth. With this range you can adjust your RC car's gearing for higher top speed (using higher tooth counts) or stronger torque and acceleration (lower tooth counts). Switching gears lets you match the terrain or track conditions without buying individual pinions.

Precise 64P pitch and 3.175mm bore

These pinions are machined to strict 64-pitch (module) specs, so they mesh properly with standard 64P spur gears. The 3.175mm inner diameter fits the most common motor shaft size used in 1/10 scale RC vehicles. The bore tolerance is tight, reducing wobble and ensuring consistent engagement.

Lightweight aluminum alloy construction

Each gear is CNC-machined from high-strength aluminum alloy. Compared to steel pinions, aluminum reduces rotating mass, which helps the motor spin up faster and can improve acceleration. The surface treatment resists wear and deformation during runs on dirt, grass, or pavement. While aluminum is softer than steel, many hobbyists choose it for weight savings in racing and crawling where every gram matters.

What's included for installation?

Every pinion comes with an M4 set screw. A hex key is also provided in the package, so you can mount the gears onto your motor shaft right away. Just slide the gear onto the shaft, tighten the screw against the flat spot, and you're set.

Compatibility with popular RC brands

This gear set is designed for 1/10 scale trucks, buggies, crawlers, and monster trucks. It fits motors with a 3.175mm shaft, common in models from Tamiya (TT01, TT02), Traxxas, Axial, Arrma, HPI, Kyosho, and Losi. Always double-check your spur gear pitch – these pinions require a 64P spur gear for proper mesh.

Frequently asked questions

Will these fit a 540 or 550 motor?

Yes, as long as the motor has a 3.175mm shaft – that's standard for most 540 and 550 brushed and brushless motors.

Do I need to ream or modify the bore?

No. The bore is precisely 3.175mm, so it slides directly onto the shaft without modification.

Are the screws included?

Yes, each pinion comes with an M4 set screw, and a hex key is included.