[Dr_T]

Yeah, that comment was more in general and not specifically about your motor. The troubling part of that quote of Vedder is that it makes it seem that more powerful motors will just run hot anyway, even at lower loads. Maybe not as hot as an overgeared small motor, but still hot...

Your experience with the TP5640 still puzzles me, I think the difference between loaded RPM and unloaded RPM should indeed, like you said, indicate how 'loaded' the motor is, the bigger the load, the bigger the RPM drop... unless..., there's something else going on and it's not the motor that's the bottleneck, but the batteries that cannot provide the over-dimensioned amounts of juice the over-dimensioned motor needs to rev up to where it wants to go? There's some similarities with 0verkill's 4S mini 8ight that also does not go as fast as expected, based on gearing and motor alone, although his over-dimensioned motor (TP29-something) stays cool.

Re the braking we talked about earlier, I think the difference in acceleration and braking distance can be explained from the fact that all the forces (drag, rolling resistance, driveline friction) the motor has to battle during acceleration, are helping it during braking. Not sure how well it holds in practise, but theoretically, the motor Torque is proportional the the motor Current (x 1/kv). So if the motor shaft really would have to endure higher Torque at braking, that should somehow show in the Currents. My XL2 does not seem to log negative Currents, but my EagleTree does, and I've never seen my braking Currents go much past 40A in the 8ight-T set-up that pulls 200+A at acceleration. Now, I don't exactly understand how braking works, as I think braking Current can be divided between a regenerative part, sent back to the batteries (that part is measured by my logger), and a part that is just dissipated in the motor by the ESC shorting the motor windings (that part cannot be measured by my set-up). I think you and Vedder talked about that once, but I did not pay enough attention then to recall exactly :).

Edit:
Without a way ahead this would be too shit of a post :D... So, would be cool if you could find a way to log some stuff. Not sure if you want to use your Monster X on this, but seeing the Currents, ripple and Voltage sag, would definitely help solving this mystery :). Were you running a low-Voltage alarm that could have indicated major sag? Maybe hard to hear the beeps when high-revving metal gears pass by at over 100 mph though :D