When relying solely on the throttle without any pedaling, most e-bikes are designed to cap out at 20 mph (ca. 32 km/h) for safety reasons. The distance you can cover depends on factors like terrain and battery capacity, but typically, you're looking at a range of 20–40 miles on throttle alone. Remember, pedal-assist modes can extend your range significantly and allow speeds up to 28 mph (ca. 45 km/h).