First I make sure there is nothing wrong with the bike. Then when I have the money in hand they can ride it, after all they own it now. If they find something wrong I'll fix it or return the money. There has to be trust involved but I can't trust that someone can ride just because they say so. There is also the factor that no matter how much experience you have getting on a strange bike is a little awkward. It is easy to drop it in the first few hours. I've sold I think eight this way and never had a problem. When I buy a bike I've never asked for a test ride either, take my chances and so far not a problem.