How to find the right RC Vehicle Transmission Gears AI guide
Written by an AI model from its trained knowledge.
What the AI looks for in RC Vehicle Transmission Gears
- Pitch or module match
- Pinion and spur must share the same pitch or module exactly, for example 48 pitch with 48 pitch, 32 pitch with 32 pitch, Mod 0.8 with Mod 0.8, Mod 1 with Mod 1; metric module and imperial pitch never mix. Mismatched pitch strips teeth within minutes even when the gears appear to mesh.
- Pinion bore size
- Pinion bore must match the motor shaft, commonly 3.17 mm on smaller motors and 5 mm on larger brushless motors, or 8 mm on the largest scales. An oversized bore with an adapter sleeve can slip and wear quickly under brushless torque.
- Tooth count within mount range
- Choose pinion and spur sizes inside the range your motor mount and gear cover allow, and check motor and ESC temperature after a change. Overgearing overheats motors and ESCs; gears outside the mount range cannot be meshed at all.
- Material for the power level
- Hardened steel pinions for brushless systems; aluminum pinions are lighter but wear fast; spurs in steel or composite depending on the vehicle's design. A soft pinion running against a steel spur wears to a point and then strips the spur.
- Set screw and flat
- Align the pinion set screw over the motor-shaft flat and use thread locker. A pinion slipping on the shaft is a common cause of gear chatter and stripped spurs.
Brands that matter
- Robinson Racing: Wide range of hardened pinions and spurs across pitches and bore sizes.
- Kimbrough: Long-standing maker of replacement spur gears for many vehicles.
- Traxxas: OEM pinions, spurs and transmission gears matched to Traxxas gearing charts.
- Arrma: Factory spurs and pinions in the module its vehicles use.
- Hot Racing: Aftermarket steel transmission gears and spurs for popular bashers.
- Team Associated: OEM transmission gears and spurs for its race cars.
- Tekno RC: Hardened gears and spurs for its racing and basher kits.
What to avoid
- Mixing metric module and imperial pitch gears.
- Aluminum pinions in high-power brushless setups.
- Gear listings that omit pitch or module and bore size.
- Setting mesh too tight; leave slight backlash between pinion and spur.
Questions
Bigger pinion or smaller pinion?
Bigger raises top speed and heat; smaller improves acceleration and runs cooler. Check temperatures after any change.
Can I just replace the pinion?
If the spur shows worn or hooked teeth, replace both, since a worn spur quickly ruins a new pinion.