Torque (at the wheel) does matter as well as power. With a hub motor, the gear ratio is typically fixed so you're at the mercy of the motor characteristics, but driven through the chain, you can change it. I used to have a low powered hub motor e-bike and it was fast but pretty useless at accelerating from stopped or climbing hills. At these very low speeds, an optional low gear would have put the motor in a higher power point on its speed-torque curve.

Though perhaps you're saying these motors are so over-rated that even close to stall torque, their reduced power output is still 250W? That would be an efficiency loss but not a power loss since they're not allowed to deliver full power at higher speeds.

>> Power is power, there is no combined "power + torque" that measures how much wind you have in the sails. Torque just characterises how much power you can get along different RPMs.

> Torque (at the wheel) does matter as well as power.

If you are getting 250 W of power at the wheel (in other units, 250 Joules per second, or 250 Newton-meters), that's what you are getting, no torque about it.

>> the EU/UK 250 W cap is so low that it seems unlikely torque characteristics would enter the picture significantly unless you're going very slowly

> Though perhaps you're saying these motors are so over-rated that even close to stall torque, their reduced power output is still 250W?

Yes, I was saying something close to that ("very slowly").

IOW the overprovisioning of the motor combined with the power cap makes the motor work much more like a "always 250 W" power source than a "250 W peak output modified by torque" power source.