[RogerM]

5.5 outdoors = 20t

6.5 outdoors = 23t
6.5 indoors = 21t

7.5 outdoors = 25t
7.5 indoors = 23t

8.5 outdoors = 27t / 28t
8.5 indoors = 25t

Those are my starting gearings and then I go up or down a tooth depending on motor temps and feel on the track.