I wouldn't trust that to move someone else's people 50, let alone my Xciting 500 - not even using it the way it's intended. Towing it by the rear wheel you aren't going to be able to steady the bike to keep it from swaying, or to keep the handlebars from turning and ripping the bike from it.
Bad idea - I recommend you don't do it.
If you mount your Xciting 500 on it - please post pictures before and after.