I'm looking for a starting point for gearing a TC3 with a 19t Chameleon2 motor. Whats a good starting roll out?

I'm looking for a starting point for gearing a TC3 with a 19t Chameleon2 motor. Whats a good starting roll out?
For a C2 and a smaller carpet track, I'd start around 27-28mm and go up from there.