I agree that the motor wind there for kv rating of the motor core is what gives you the different speeds. It dose seem silly to change gear ratios to achieve this as it would be costly to manufacture different gear sets.
I was told my code 9 was 8.9 rpm - volt. That was the fastest wind I could get . What's the fastest they make code 8 ?
I also think my motor looks a little different to the one in the pic inside. The windings are exposed and the motor casing is more of a open frame. I guess to allow better heat transfer
It still has me stumped then Why they mark a wheel size on the motor casing? Mine has 26 on it but its doesn't make sense even if the marking was just a recommendation to the wheel size 26" you would expect my code 9 to be marked 20" or 24" and 26" to be marked on a slower wind like code 12 or so.