ebikesca, an excellent "e" business, sells Shengyi, but I think their motor is smaller. However, they may be able to help you. I think the most difficult part of the repair is removing and replacing the bearing, but that can usually be accomplished with the proper size socket and a vise. Ask them or take a look at YouTube. I'm surprised that Rad has such poor CS; maybe they're devoting too much manpower to fighting lawsuits.