I decided a few years ago to reduce the herd a little, so put some bikes up for sale. I wasn't going to allow any test rides by people whose skill or integrity level was unknown to me. This is maybe a little contradictory because I wouldn't want to buy a bike I had not ridden, but my bikes are all well cared for and it shows. I stuck to the no test ride policy (with one exception), which led to some bitter conversations with prospective buyers. They'd tell me how interested they were in the bike, how experienced they were, blah, blah, blah.
The exception was with a nice silver and blue '82 CB900F I was selling. It looked and ran basically like new, even though it was 15 or 16 years old at the time. A guy told me he was very interested and wanted to take it for a ride. I said no, but he nagged me, telling me how interested he was, how he'd wanted one like it ever since they'd come out, in that color, etc. Since he seemed sincere and I wasn't getting much action on the bike from the ad, I relented. As soon as he cleared the driveway, he red-lined it and ran through the gears. The bike had an open Kerker exhaust on it, so I could hear him way down the road, just beating the heck out of it. When he got back, he said he'd think about it and let me know, then left. Never heard from the SOB again. I am not a particularly violent person, but at that time I would have cheerfully broken his neck.
I stuck to my policy after that. It made it harder to sell the bikes, but they all eventually sold.
Greg
'75 CB750F