All riders begin together as part of the peloton, although individuals are actually members of separate teams. The principal concerns affecting road race performance are team tactics and drafting. Because riders remain grouped in the peloton, only the few who are in the front at any one time face the full effects of wind resistance, while others can easily maintain the peloton's pace by drafting. Usually, breakaway riders can outdistance the peloton only when the complex dynamics of team support allow it. The major exception to this rule, as discussed later, occurs when the peloton encounters hills.
Time trials pose different problems.
Individual riders face the wind and the clock on their own. Individual power and endurance ultimately determine performance. Triathletes are essentially engaging in a time trial during the bicycle leg of their competition. Criterium races are mass start events held on a small, looped course. Riders perform multiple circuits of the course, with high-speed sharp turns.