When I had my bike I would always nod at other bikers, not scooters though (Vespas, Lambrettas etc.) unless they nodded first! I can say I would NOT partake in the Ranger wave. If my Ranger was totally kitted out and I came across another kitted out, that is different, we are obviously both enthusiasts, but me in my nearly stock Ranger waving to another nearly stock Ranger... No. Where do you draw the line? Should I wave at the guy across the street because we have the same roof tiles?
What I'm trying to say is if you feel like waving... then go ahead and wave, just don't get all angry if they don't wave back, not everybody is as enthusiastic as you.
True story... A couple of months ago me and two friends were loading the car up to go beach fishing early one morning. A passing car honked and the two guys inside waved. We noticed their fishing gear on the roof rails!... A fishing wave! Brilliant!