Some kinda low "load rpm" with these motors. do they mean load with a prop?
alot of things are confusing me...

Graupner 6311 SPEED 600 BB SP 7.2V Motor:

free rpm; 28,100
load rpm; 9,400 (!?) sounds very low

i have these motors. and on the package it says 21,200 rpm... (7,2v)
now where do they got the 28,100(8,4v) from?
i know the mat and its impossible to go from 21000 to 28000 rpm with just 1 more cell