I bought online from a company called ElectricWheels. The company really sucks. I have to say I did not do enough Research. But I'm not sure that I can do better since I have not found many discussions on reliability, failure modes of various eBike. I'm not into performance. I just want a practical bike that is not too expansive and it can carry me to work. I work on top of a small hill, 200 meters above Sea level. The darn bike failed on my first attempt to climb that hill, at less than 20% of climbing. I ended up to push the bike up remaining 80% of the hill. I can not imagine such un-reliable product. Since I rode about 20 miles OK on almost flat roads on 3 other rides, I concluded it must be the hill. The 250W motor simply does not have enough power to climb the hill and burnt it out. Seems really stupid design without any safeguard of overload.