But if you go by this thread:
http://www.ausrc.com/forum/showthread.php?t=15868
He's being told his esc blew as he ran the 20t pinion (stock gearing) and not the 25t pinion (optional included)
so doesn't that contradict what you are saying?
By your logic he should have gone down to a 12/13 perhaps, by theirs, the smaller pinion is what fried the esc