When I first started riding with the ladies for our weekly road rides, they didn't often say hello to other cyclists and in fact made fun of me because I of course said hello to EVERYONE in standard Bexter style! Yes, they do say hello more often and I do think a positive, outgoing attitude is contageous. I have witnessed the standoffishness of some cyclists and God only knows what their deal is. I agree with people's suggestions in this thread. Lead by example -- be cordial, helpful and supportive to everyone everytime and maybe in time, attitudes will change. Not sure how the width of one's tire impacts one's attitude. Maybe it's a size issue...