However , athletes will select their start position based in order of their Olympic rankings at the athlete briefing in Rio .
Start numbers are drawn at random and assigned in groupings to National Olympic Committees , determining where athletes rack their bikes in transition .
Athletes will select athletes ' start position based in order of their Olympic rankings at the athlete briefing in Rio .
Start numbers are drawn at random and assigned in groupings to National Olympic Committees , determining where athletes rack their bikes in transition .