Originally Posted by
jmcvicker
I read a note from someone who said "take brushed turns and halve them to get a similar performance brushless motor turn number".
So, that seems to work.
27T brushed -> 13.5 brushless
19T brushed -> 10.5 brushless
13T brushed -> 6.5 brushless
10T brushed -> 4.5 brushless
something like that. Brushless motors are not all the same - so the formula isn't exact - but works for a ballpark. Also note that brushless gearing is "way higher" than brushed in some cases. So, adding a few teeth on the pinion is typical when moving from brushed to brushless in the same "class".
That's a good "rule of thumb" but in reality, your list could be offset by one
27T brushed -> 17.5 brushless
19T brushed -> 13.5 brushless
13T brushed -> 10.5 brushless
10T brushed -> 6.5 brushless
7T brushed -> 3.5 brushless
going from 27t brushed to 13.5 brushless was a huge leap in gearing for me at my local track. I went from 8.2 down to 5.1