3 months after the left motor winding died, the right motor winding died.  This one died in the dead of winter no less & smelled like burned enamel.  It was last rewound on April 29 so it only lasted 7 months.

The left windings lasted a solid 10 months.  The right windings were staggered.   They're rated for 150C & they're confirmed to melt at 300C.  Lower temperatures allow longer duty cycles, but all temperatures eventually melt.

Suspect running faster more often is burning them out.  At this point in the history of motor rewinding, nothing new could be added.  The question is when is rewinding motors going to take more time than designing a temperature sensor.  

The leading ideas are thermisters & thermopiles.  Temperature sensors are not standard in electric bike motors, despite Louis Rossmann's vlogs.  

Guys just epoxy them to the motor windings.

This one is siliconed to a motor case.

The leading idea is cutting down the heat sinks since they're not doing anything, permanently farstening thermisters to the heat sinks next to the motors.  The heat sinks did a good job tracking motor temperature, but didn't remove any heat.