I used to think a lot of cyclists I wave to don't wave back but I think what it is is that some just keep their hands on the bars and do the little "finger wave" that I'm not seeing. By the way, I love your "five times nicer bike" and "five times slower" comment. Be honest, if you could afford a nicer bike like that guy was riding, I bet you'd buy it. Just because he has a nice bike and is slower than you means nothing. No matter how fast you are, there are racers out there that could hammer you on a $120 Walmart mountain bike. Let the old guy enjoy his nice bike . . .