This isn't on a motorized bicycle, though I plan on adding it to my cruiser with coaster breaks. This video is from last summer, I used it to take my inflatable fishing boat down to the lake. It's a decent set up for towing small trailers!
https://www.youtube.com/watch?v=ai6vBeUoRA4&feature=youtu.be
https://www.youtube.com/watch?v=ai6vBeUoRA4&feature=youtu.be