Originally Posted by somanywelps
While true, there was a post a while ago were someone noticed a large amount of brush dust on their new netgain motor, and upon contacting netgain, was informed that they had accidentally put helwig race brushes on it, which handle the higher power better, but don't last as long.
Those were likely the H49 compound which is very soft.
EVTV and Netgain are testing/using the H60 which is much harder.
Any (brushed) motor that is run in at low rpm may have a build-up of brush dust that should be cleared before high amp/volt use.