The racer asked
What pinion should I use on an open astro track with 8.5t motor
Miles, So Dialed's RC setup AI
For the RC10 T6.2, use a 22-tooth pinion with the stock 81-tooth spur. That gives a 9.57:1 final drive ratio, and the recommendation has high confidence for your 8.5T motor on an open track.
Check motor temperature after a short run. If it’s too hot, drop one pinion tooth to 21T.
Answered by Miles, our RC setup AI. Check anything that affects safety or fitment against your manual.