In situations where there are as little as two riders, drafting behind another rider allows the rider doing the drafting to conserve around 25 percent of his or her energy.
In a “paceline”, with three or more riders, each rider can take turns “pulling” at the front of the paceline for shorter periods of time before rotating to the back of the paceline, which allows all of the riders in the paceline to conserve up to 30 percent of their energy. The more riders in the paceline, the more energy everyone can conserve.
In a peloton, a rider will have much more of a chance to “sit in”, and not do any work pulling at the front. If a rider does no work at all, he or she can conserve 45 percent or more of his or her energy. Sitting in does not apply to the single rider only. Whole teams can sit in, if they chose to do so, which would give them a greater reserve of energy to launch an attack, or just conserve energy for a harder upcoming stage.
Of course, if you are in a team that has to chase down a “breakaway”, you have no choice but to go the front of the peloton and work like a madperson.
I do know that if bicyclists tried to ride in a vee they'd be very limited in numbers, because roadways aren't as wide as the sky!
If fact, there are times when riders ride in what one might visualize as a half-vee formation, and angle diagonally across the road. It is called forming, or riding in, an echelon. This is done when the wind is either perpendicular to the riders’ direction of travel, or coming at them at an angle. Since, as Jackie writes, “they'd be very limited in numbers because roadways aren't as wide as the sky” the peloton will usually break up into several echelons. If a team is trying to protect one of its rider’s placement on the General Classification (GC), they had better make sure to get him or her into the first echelon, because the rear echelons usually get “gapped” quite badly, and sometimes “dropped” altogether.
an "X" formation
Digressing from the benefits of drafting, and delving into strategy and tactics, the X formation would indeed allow a team to respond to many different situations. That’s not to say, however, that a team should always ride in an X formation. Different goals require different formations. In some situations, formations are moot. If a team, or rider, attacks with enough energy, the peloton can be split and fragmented, a breakaway group can be fragmented, and riders can “crack” and get dropped off of the back. If riders can’t “keep the wheel” of someone in front of them, i.e. draft, and wind up getting dropped, they certainly can’t take part in a formation.
