Laser Mark 250W on Motor
Laser Engrave 250 Watt Continuous Power Rating on Motor Side Plate. This is Truthfull. ALL Hub Motors Offered by Grin Have an Operating Point (RPM and Allowable Temperature) Where They Can Only Sustain 250W.
Contrary to common assumption, European ebike legislation does NOT limit the maximum output power of the electric motor to 250 watts. Rather they define a maximum continuous rated power output for the motor when it has reached thermal equilibrium, at the manufacturer defined maximum operating temperature.
That's why industry leading Bosch and other "EU compliant" systems will pull upwards of 800 watts of battery power. Ebikes would be far less popular in europe if they were truly limited to just 250 watts.
Unfortunately there is no such thing as a meaningful or unified power rating for electric motors, as we have explained here, hence we don't generally classify motors as having a specific power, and none of our motors have a formal power rating engraved on them because there is no such thing. But this has caused difficulties for customers who need some official power spec to demonstrate compliance , so we offer a laser engraving service to those who need this.
Technically even our largest hub motor will struggle to put out 250 watts of mechanical power continuously if heavily loaded and running at a very low RPM with poor air flow, and in a worst case ride situation with thermal rollback enabled they will indeed become limited to 250 watts or less. As a result we have no problem to engrave a 250 watt rating on the motors to facilitate compliance with this poorly spec'd legislation, and will gladly back that up with hard data when called for.