Spent Saturday wandering along the Grand Union Canal towpath from King's Langley to Hanwell. There were plenty of cyclists on the path. And the majority were courteous. Usually a ring of the bell or a greeting, followed by a 'thanks' as we stepped to one side, and sometimes a few words about the relatively fineness of the world and the increasing proximity of an evening filled with beery goodness.
But, alas, we were passed by a half dozen cyclists who weren't. Sadly, they all looked the 'proper' cyclist: with the helmet, the lycra, relatively expensive bike and kit. Modus operandi was passing too fast, usually with little warning (one did shout "watch out!" as we were forced into the nettles), and never bothering with a "thanks". They did get a sarcastic chorus as they sped into the distance.
Now, as I'm cyclist and a courteous one at that, I know and can reflect upon this being a minority of cyclists. But, if I wasn't, I could easily see myself remembering that minority and coming to a very negative opinion of cyclists. Which is a shame, but I think it does partly explain why relations between cyclists and pedestrians and motorists are so antagonistic.
On the bright side, we were passed by plenty of kids who looked like the ASBO-imbued hooded nemesis of godfearing Dail Mail readers, and they all without fail gave us room and said 'thanks' as they passed.