Ratamero's model exhibits self-organized convection-like behavior which Trenchard described as a phase of peloton behavior. There are several factors to look for when buying a road bike, especially if it’s your first bike. Unlike parts such as wheels, tires, seats, etc., which are prone to wear and tear and more likely to be replaced or upgraded down the line, the frame stays on the bike for as long as the life of the vehicle. Meanwhile, cyclists taking the challenge more seriously can choose to raise money for charity through sponsorship. Being close to the front is also critical in strong crosswind conditions. Riders for a paceline, such as an echelon, sequentially change positions at short intervals so that no one rider must long accumulate excessive fatigue from facing maximum wind resistance at the leading edge. Echelons are necessarily limited in size by the roadway's width.