XRAY RX8 Tuning Pinion 21T 7075-T6 - Arrowmax AM-RX8-348521  [AM-RX8-348521]

Upgrade 21-tooth pinion for XRAY RX8

The Arrowmax AM-RX8-348521 is a 21-tooth pinion made for the XRAY RX8 range, machined from 7075-T6 aluminium and treated with a hard coating. It is intended as a direct 2nd-stage replacement for RX8 cars where tooth count changes are used to dial in gear ratio and motor load.

Key points hobbyists should note:

• Material and finish: 7075-T6 aluminium finished with a hard coat to help resist wear from repeated spur contact.
• Role in drivetrain: acts as the 2nd-stage pinion to modify final drive ratio and tune the balance between acceleration and top speed.
• Compatibility: engineered for use with XRAY RX8 setups; always verify RX8 pinion dimensions and shaft fit before swapping parts.

Fitting tips and tuning advice

On installation confirm proper spur-to-pinion mesh and tighten the set screw to the RX8 motor mount torque spec. Clean away any machining residue before the first run and inspect mesh again after brief use. Switching within the 16T-21T band will alter RPM and drivetrain load predictably, so update ESC settings and gearing to suit your track conditions.