XRAY RX8 Pinion Gear 21T by Arrowmax AM-RX8-348521  [AM-RX8-348521]

Pinion gear for XRAY RX8

The Arrowmax AM-RX8-348521 is a 21-tooth pinion gear produced for the Xray RX8 platform and finished in 7075-T6 aluminium with a hard coat. It is intended as a direct replacement 2nd-stage pinion for setup and tuning work on RX8-spec cars where changing tooth count adjusts effective gear ratio and motor loading.

Key points hobbyists should note:

• Material and finish: 7075-T6 aluminium with a hard-coated surface to resist wear from spur engagement.
• Role in drivetrain: used as the 2nd-stage pinion to alter final drive ratio and influence acceleration versus top speed trade-offs.
• Compatibility: designed for the XRAY RX8 series as stated by the manufacturer, use only where RX8 pinion geometry is required.

Installation and tuning notes

When swapping pinions, verify proper mesh with the spur gear and ensure the set screw is torqued to the manufacturer’s recommendation for the RX8 motor mount style. Check for burrs or machining residue before installation and re-check mesh after initial run-in. Changing between the 16T–21T range will have a predictable effect on RPM and drivetrain load, so adjust ESC and gearing choices accordingly.