Around here peopel on bikes do not say "hello" unless they know eachother. Especially if you are on an oldish bike or one with rack and fenders, do`nt even try!
First time we went to the big city to ride our B`s we were not prepaired for the "puppy effect". Walking up a really steep hill suddenly there was a man on a B in front of us. He was wery suprised (just like us) and with one big smile said "Bromptons!!" We said nothing, just " uh, yes.." or something like that.
Now we sppeak with peopel all the time (but newer peopel on bikes). They say "what a smart bike" and ask where you can buy one.
I think that for the man on the black B (sounded British by the way) we are two of those in suits..
Newer met a B after that apart from two in Copenhagen this May.