I let my brother ride my bike one day (with me) and he leaned it up against the brick chimney outside of my house. I wish he'd leaned it up against the bars/saddle but he leaned the frame on the corner. Sure enough, it rolled and left a 4" scratch on the top tube. I didn't say anything but I was a little pissed. I ended up selling him the bike (he needed it more than me anyway...) I dont know, I guess I'd loan a bike to him again but might also remind him that it better come back in the same condition that he took it in. He's really the only person I know that rides so I guess I wouldnt have to worry about loaning to anybody else.