Kim asked a very good question recently: “Why is it suddenly okay to do things on the bike that you wouldn’t do elsewhere? Nose blowing over the road (or an unlucky rider behind) being one that quickly comes to mind.”
Think about it. Flying snot rockets. Spitting on the pavement. Running red lights. Taking roundabouts in the wrong direction. Even littering. For many cyclists, things we’d never normally dream of doing in public often become far more acceptable as soon as we throw a leg over our bikes. It’s as if the flow of endorphins causes reality to get parked when we’re out riding. Now, I know not everyone does these things. But many do. Be honest. How many have you been guilty of at one time or another?
Carbon Addiction 
OK, I admit to occasional spitting. I don’t see it as a big issue; I spit on the grass or roadway, and it’s soon gone. On the other hand there are gel packets and tubes – how is it that people can’t put them in their pockets and take them home (or to the nearest bin)?
I cannot lie as I have been known to spit and even use the bush hanky especially in a race. I simply couldn’t carry enough tissues to cater for my snoz… I do however move toward the back of the group that I am in when doing so.
As for rubbish etc, I very much agree. I don’t see why people can’t simply put them in their pocket and dispose of when off the bike.
You caught me blowing my nose on Saturday when you were behind me. Cannot deny.
Have spit for sure, but only onto grass and always check there is noone else around before doing it in case it offends.
Definitely never do the bushmans blowie however – I have no idea why people think that’s OK.
Don’t litter either. Always take my stuff with me.