Hey Pat, I don’t know what I did to rile you up. I am interested in real world data, I commented because your back of the envelope math didn’t make sense to me. I believe you that there is could be RPM limit and that is wouldn’t be good to over that. I am interested in these motors/power train which is why I have been following this thread for some time.
Efficiency (to me) is something like watts in from the battery vs watts out of the motor. Rpm is a speed of the motor. Max rpm possible based on Kv vs load rpm would give you a number on how much you are loading up the motor. I haven’t seen 80% around, but you must have based on your testing. Actually I would guess that it would load up worse on higher kv motors with the same drive train. You also would probably have worse efficiency (watts in vs watts out) as well.
I’m the first to say I don’t know much, hence why I follow these forums. Joined in Oct '16 if you didn’t see that in my profile, but I tend only log in when I want to comment on something. I see you joined in May '17, but really I wouldn’t have thought to check on that to see if a person is worth talking to.