qwerkus said:
How do you guys cope with motor overheating in such hot places like Phoenix ?
Doesnt' affect it significantly.
On the SB Cruiser, my MXUS 4504 on the left side, used as the only motor with the generic 15FET at around 1000-1500w cruise, 20MPH, will reach about 60-65C peaks at the windings, when it's 45C ambient. That drops in seconds to the mid 50s once acceleration or braking is over, and in minutes during cruise or at stop drops to low 50s.
I never measured the old 9C 2807 I used ages back on it and CB2, but it had to work harder to do the same job, with less mass to absorb spikes of heat, and it probably didn't get that much hotter.
A very small geared hubmotor that can't shed the heat it makes easily, that starts at a higher base core temperature (let's say, sitting in the direct sun on a 45C day so it starts out at >45C), might have a harder time of it. I used a little 350w Fusin front geared hub (but probably saw twice that power or more at full load) on DayGlo Avenger, and pulling a trailer full of St Bernard a couple of miles got it pretty toasty; I don't recall the ambient temperatures, but one time it got hot enough to cause the halls to temporarily malfunction. Wrapping it with a rag and pouring water onto that cooled it enough in a few minutes to keep going, but it kept heating up and stopping. If it had been kept to the design limit, in normal use, it would not have had a problem.
A small DD hubmotor would probably not have had that problem (the 9C, for instance, never did that, even when run at more than twice it's "rated" power level). I worried that they would, but it never happened.
Dogman smoked one of those 9Cs in the DeathRace, becuase the tire on that wheel was basically flat, but he kept racing anyway. The extra load on it plus already pushing it way harder than it was designed for was too much for it. That wouldn't happen in normal use.