UCI CYCLING REGULATIONS  Chapter V TEAM TIME TRIALS  (numbering of the articles modified on 1.01.05, former article 2.5.012 was  abrogated on 1.01.04; and former article 2.5.020 was abrogated on 1.01.03).  Mixed teams as defined in article 2.1.004 are forbidden.  There are six riders per team for the world championships, composed of three men and  three women of the same nationality. An incomplete team may not take the start.  The participating teams are defined in Article 9.2.021.  (text modified on 1.01.05; 1.01.06; 1.10.06; 1.07.12; 1.01.19; 1.01.21).  (text modified on 1.01.05; 1.01.07; 1.07.12; 1.08.13; 1.01.19).  It shall be sufficiently wide and avoid excessively sharp bends.  From the start of the race, the circuit may be used only by the riders in the race and the  vehicles following such riders.  A training session on the circuit must be organised the day before the mixed relay at  world championships.  (text modified on 1.01.19).  (text modified on 1.01.05).  2.5.001 The number of riders per team is determined in the programme - technical guide - and  must be at least 2 and no more than 10. For mixed relay events, the number of riders  per gender must be at least 2 and no more than 6. The maximum team size for mixed  relay events shall be no more than 12.  2.5.002 The distances for team time trial races shall be:  2.5.003 The course shall be safe and perfectly signposted.  2.5.004 The distances remaining to be ridden shall be indicated clearly every 10 km at least. The  last kilometre shall be signalised by a red triangle. For uphill races, each km shall be  indicated.  Participation  Distances  Course  Category  Maximum distance  World championships  Other events  Men Elite  100 km Under 23  80 km Junior  70 km Women:  Elite  50 km Junior 30 km Mixed  relay  Elite  Under 23  25 km per gender  50 km per gender  E170421  ROAD RACES  53 