I'm running a motor that has a Kt value of 105 according to the manufacturer. I've got an input voltage of 49.4V (as read by VESC Tool software). Therefore with no losses and a max duty cycle of of 95%, I'd expect to hit RPM values of around 49.4 x 105 x 0.95 = 4928RPM. (I have the max ERPM software limit set well above the max I should ever see in practice, so that shouldn't be doing any limiting).
In practice, I'm maxing out at around 4430RPM, which is 90% of the ideal max of 4928. I imagine there's some loss in output voltage; particularly I've been told that higher PWM frequencies decrease effective output voltage, and so I'm wondering if that might be what's at play here. Just curious as to whether a 10% loss seems about right. Since it's a new motor that I'm testing, it's hard for me to say whether the Kt value of the motor isn't specified correctly, whether I've got a bad software setting, or whether everything is just normal.