Riding in a Group
-With group I mean a peleton, a tight group of riders that follow some rules to optimize efficiency. A group achieves a much greater speed than a single rider with the same effort. It does require that all riders are in roughly the same shape. Small differences can be compensated by letting stronger riders spend more time in front, which takes the most strength because they are the only ones who feel the full force of the headwind.
-When I ride in a group we ride in two columns. Everybody keeps a distance of about 1/2 wheel diameter to the rider in front to catch as much of the draft as safely possible. When the riders in front get tired, they accelerate a bit, go to the sides (one a bit ahead of the other to avoid having four bicycles side by side), and let the group ride through the gap. (Obviously this works better if there is an even number of people.)
-Some groups regulate how long people stay in front, and some use a rotating peleton where the left column is slightly slower than the right. The right rider in front shifts over to the left column after a (very short) time in front and falls back. This makes it hard to talk though.
-The key to riding in this way is keeping the speed absolutely constant. A gap of 30 cm at speeds of 40 km/h does not leave a lot of room for error. This means that