Losi 22 2.0 gearing
 

What the best gearing to run for an astro (hnmc) track for a losi 22 mid motor and 7.5 t motor
Cheers Zak

There's a suggested gearing chart in the manual mate which are a good starting point. These are set a bit low and don't take into account boost and timing advance etc ( if your speedo has this ) Also read the guide or website for your chosen motor, this will also help. Manual says 21 pinion on a 78 spur.
HTH

As said your motor and esc manual and the guide in the 22 instructions is a good starting point.

If it helps, or maybe not, I'm running 25/76 with a nosram pearl istc and nosram pure 8.5 octa wind, around Stotfold's astro track.