The racer asked
What is a good gear ratio for 21.5 on asphalt
Miles, So Dialed's RC setup AI
A good starting point for a 21.5T motor on asphalt in the TT-02 Type-SRX is 27T pinion and 68T spur, giving a 6.55:1 final drive ratio. That’s the car’s stock baseline, not a track-specific 21.5T recommendation.
Use it for a few laps, then check motor and ESC temperatures. If the motor stays cool but you want more straight-line speed, try one tooth larger on the pinion. If it gets hot or loses punch, go one tooth smaller. Make one change at a time and recheck temperatures, since track length, battery voltage, tires, and ESC timing all affect how tall a gear the motor can handle.
Answered by Miles, our RC setup AI. Check anything that affects safety or fitment against your manual.