Our decades spent transporting ourselves in sealed cans shooting down a conveyor belt have given us the habit of ignoring each other in transit. Even using mass transportation by bus or rail, how often do you strike up a conversation with people in forced proximity?
Bicycling puts us in an odd position. As individuals on individual conveyances, we pursue our own schedules at our own pace. No longer sealed safely away from unwanted communication, we can't just keep the windows rolled up and avoid eye contact with other cyclists we might pass or who might pass us.
If passing speeds are fast enough, the encounter can be handled with a quick greeting, a wave or non-committal grunt. But what happens when speeds coincide? There you are.
I don't have a lot to say when I ride. True, I have ridden with friends and chatted away, but if I start a ride alone I settle into a solitary groove.
When I went to a university where throngs of cyclists filled the car-free streets, we mostly ignored each other except to react to the flow of traffic. You could try to start a conversation if you wanted, but no one expected a lot of camaraderie. But in the outside world, where cycling for transportation makes you weird and different, cyclists tend to develop some level of group identity. Like any minority, the accidental group becomes something of a subculture. Subsets within it lay claim to leadership roles. In some cases a siege mentality sets in. Members of the subculture expect solidarity and conformity from all other members. As each group competing to define the whole expresses its different expectations, conflicts can occur, but all the sub-groups accept the notion of a greater subculture. We cease to be people and instead become Bicyclists.
To wave or not to wave? To chat or not to chat? As people we don't think too much about it. We act according to our personal level of sociability. As Bicyclists we have to decide how to reach out to fellow two-wheelers.
Then there's the drafting issue. I'll take a little shelter behind almost anyone, though not super close if I don't know them. I just never know whether to say anything. When I draft a motor vehicle I assume I am invisible. I must take care of my own safety, but I'm not obligated to socialize.
On the rare occasions when I encounter other riders going the same direction I am, I generally flow through them at a slightly higher speed, with a nod, a smile and a greeting in a mild tone. If other cyclists are faster, I won't catch them or they won't hang back with me. Only occasionally will someone's speed fluctuate within a range that extends the encounter. Or they might jump in my draft.
These questions probably only arise on country commutes with long stretches of open road. In city streets, cyclists are too busy with basic survival to worry too much about their own social dynamics. And when cycle transportation reaches the tipping point and becomes a majority activity Bicyclists become people again. We can all just be our sunny or grumpy selves.