I've never raced a roadie because my bike wouldn't let me (generally). What I find though is if I give nod to a mountain biker on the other side of the road, I always get a nod back. It's never so when I nod to a roadie... I honestly wonder why. Anyone?
I think its probably that sound of agressive new world disorder music that seems to surround you, especially when you're cycling up hills.
The roadies probably just assume your nodding your head to the beat and dont want to infere with your moment.

