[HNaTTY]

250 watts is the legal limit in the EU, whereas most states in the US consider e-bikes providing up to 750 watts of power (about 1hp) as still "bicycles" (meaning no registration, license requirements, insurance, etc). A lot of the retail bike manufacturers are designing motors for the 250 watt limit unfortunately, and although I have it on good authority that many bikes actually exceed their reported power limits, they're still dinky compared to DIY kits.