Remember kids... always wear a helmet. (The almighty bikeradar helmet thread)

IMO its a crap elitist cycling term, to refer to the 'non-trendy commuting cyclist's, usually riding with seat too high leading to 'bum-rock' and in too high a gear leading to 'nodding'.

Someone with an uncool bike. Right. I sometimes nod but only when I'm listening to terrible hip-hop.