when you see guys biking in a tight, single file row, it's called drafting. conceptually, its the same thing you see in auto racing. the basic premise goes that the person in front takes all the wind and you just float behind them exerting a fraction of the energy to achieve the same speed.

Man Who Screams Like Woman received a primer on the art of drafting from a friend because they are about to bike across the state of iowa together. it would seem that cooperative drafting has quite the rituals around it, for both safety and efficiency. for instance the guy in the front of the draft-line is not responsible for watching the road. he's busy working his ass off trying to keep a strong pace for the people behind him. the second man in line is charged with spotting any obstacles in the path where upon he alerts the front man.

additionally, when the lead man's time is done he announces this in some way so the next guy can get ready to step up and the third guy can prepare to birddog the road. the lead guy might yell 'i'm off' or something of the like and swing out of line falling to the back. the physics of the whole dynamic jettison the pack ahead of him where they will slow down a bit to let him catch up. once he's caught up he'll yell 'back on' so they can resume a hearty clip.

the first, and last, time i ever participated in a group ride which included drafting i was behind a stocky female i called sergeant bilko (in my head only). we didn't do all the fancy calling out and stuff because, well frankly, we didn't know about such etiquette. i spent most of the time staring at my front tire as it related to her back tire. it gets to be quite mesmerizing at about mile 30 and you'll find yourself zoning out. zoning out until you hear a funny noise and look up only to catch, square in the face, a gelatinous wad of chunk-laden snot shot from bilko's nose under her armpit (ala farmers blow). i heard/saw her loading up the other barrel and only just escaped the second salvo to the very great chagrin of the guy behind me.

in summary;
1. drafting is an efficient way to travel
2. there are numerous reasons to have rules
3. big girl equals big snot
4. it is totally possible to exfoliate/burn three layers of skin off your face and live to tell about it.