The classic distances for Audax UK events are 200, 300, 400 and 600km, and each rider carries a “brevet”, a card on which stamps are collected at control points to prove that the ride has been completed.
The set time limit for an Audax makes no allowance for meals or resting, so riders must manage their own pace to build up time for any stops.
The name Audax ('audacious') hints at the Italian roots of the sport, although it was in France at the start of the twentieth century that the rules were formalised.
'Randonneuring' is a particular form of Audax in which individual cyclists choose their own pace rather than riding at the speed of the group, and this is the most popular version in the UK.
Audax UK oversees the running of Audax events in Great Britain and Northern Ireland. It recognises anyone who has completed a 200km cycling event as a 'Randonneur'.
The Paris-Brest-Paris remains one of the best known Audax events, but there is a British equivalent – every four years. Audax UK organise the London-Edinburgh-London ride, one of the most challenging any cyclist is likely to attempt.
Many Cycling UK members enjoy riding in Audax UK events, and many cyclists are members of both organisations. Many Audax rides are organised by Cycling UK members.