Originally Posted by Nightshade

It's simple really. You are all out there taking the same life threatening risk as each other. Makes no difference what you ride or where you are at least giving a head nod as acknowledgement is a polite thing to do.

Even as a cager I give a a wave to bikes as acknowledgement of the risk they are taking every day by riding. Not too often I get a wave back but it doesn't matter to me at all.