Without the torque-speed curves for these motors, you just can't tell. The actual graphs are at http://www.go-ev.com/images/003_09_01_WarP_9A_Graph.jpg http://

Without the torque-speed curves for these motors, you just can't tell. The actual graphs are at http://www.go-ev.com/images/003_09_01_WarP_9A_Graph.jpg http://www.go-ev.com/images/003_09_01_WarP_9A_Graph.jpg and http://www.go-ev.com/images/003_09_02_WarP_9_SpreadSheet.jpg http://www.go-ev.com/images/003_09_02_WarP_9_SpreadSheet.jpg My guess is that the motor is actually incapable of producing its full torque at higher RPM. Correct. At 100 ft/lbs the speed drops to just over 2000 rpm. I would guess these motors have a thermal fuse wound into the stator coil (source: spent a summer in a rewinding shop), and if he tries to drive them much outside the design limits, they'll simply cut out, perhaps permanently. EDIT: the datasheet mentions a temperature snap switch, so it sounds like they have a non-permanent cut-out on thermal overload.