Peloton phase oscillations

• The nature of mass-start bicycle racing is explained; peloton is defined.
• A peloton is a complex system; outlined are its system properties and principles.
• Two equations define coupling principle in pelotons.
• An equation is given as the basis for a computational algorithm.
• Peloton density oscillations and phase regime for oscillations are modeled.

A peloton may be defined as two or more cyclists riding in sufficiently close proximity to be located either in one of two basic positions: (1) behind cyclists in zones of reduced air pressure, referred to as ‘drafting’, or (2) in non-drafting positions where air pressure is highest. Cyclists in drafting zones expend less energy than in front positions. Qualitative observations of pelotons indicate oscillations between two primary phases. The first is a high density, low speed/power output phase. The second is a synchronized, low density, high speed or power output phase. Pelotons are observed to oscillate between phases, and mixed phases occur. Principles determining the first phase are coupling due to the energy savings of drafting, collision avoidance, and continuous passing. Principles determining the synchronized phase are similar, except that minimal passing is observed in this phase as cyclists approach maximum sustainable outputs. Phases self-organize as cyclists proceed through output thresholds, while strategic and tactical considerations are secondary. A computational simulation with an algorithm combining a coupling ratio, passing time, and constraints on angles of alignment, separation and cohesion (flocking rules), demonstrates phase oscillations.