As per California's e-bike law, anything faster than pedal-assist Class 3 bikes (which are capped at 28 mph) is legally a moped or motorcycle and requires a license, registration, insurance, and a minimum age. Amazon was selling plenty of things that weren't any of those — electric two-wheelers advertised at 40-plus mph, including one listing claiming 43 mph from a 5-horsepower (4,000-watt) motor, some with motorcycle-style frames. Critics call them "hooligan bikes."

The change came after KCRA 3 Investigates reached out to Amazon about the problem . The company said it has notified marketplace vendors that their listings must meet state law and has already delisted some products.…