All the challanges are based on one guiding principle: ride the challenges with your human powered vehicle or craft from the beginning to the end, as fast as possible in a self-supported fashion. 

In particular:

1) When and where: the start date is indicated at the bottom of the page of each event. The ending date is only a formal date as there is no finish time cut-off. The Venue (bottom of the page) is the starting point of the challenge.

2) Spirit: the challenges are intended to be self-supported, GPS-timed and the clock runs non-stop (also by night!) starting on from the common departure to the arrival time of the single partecipant.

3) Modus operandi: to complete the challenges, a rider may resupply food and/or equipment, rent a room, launder clothing, even service their bike at commercial shops along the way. The intent is to ride unsupported between towns, and function self-supported when in towns. Any services utilized must always be commercially available to all challengers and not pre-arranged[1]. No private resupply, no private lodging.
The challenges require that every challenger—from those living along the route to those living on other countries—have an equal playing field. Therefore, outside assistance[2] with navigation, lodging or resupply is prohibited. Visitation from challengers’ family or friends during the challenge itself is prohibited.

4) Trails and Routes: challengers must always ride 100% of the trail/routes provided by the Organization in .GPX format. The use of a GPS is compulsory as witness of the complete ride of the trail and for timing purpose.

5) Advancing: advancing (forward) on the route by any means other than one’s own muscular powered vehicle or craft is strictly prohibited (pushing, pulling, hauling are permitted). The challenges are solo challenges, however, racing in the company of other challengers is tolerated. Each rider must maintain separate gear. One first aid kit per rider is compulsory.
In the event of a serious mechanical or technical problem that renders a vehicle or craft unrideable, a rider may hitchhike[3] by motor vehicle in ANY direction to repair the problem. The location of the incident must be well documented by SPOT tracking or other GPS logger. A rider may also receive assistance returning back to the exact location of the breakdown to begin forward progress. The entire incident, form breakdown to return to the route must be fully documented by GPS.

endnotes
[1] “Pre-arranged” is defined as prior to the start of the race clock.
[2] “Outside assistance” is defined as any third party assistance in navigation or lighting and any non-commercial assistance in food resupply and/or lodging. A service is deemed ‘commercial’ when it is for commerce, equally available to all racers.
[3] Racers may accept motorized transport backwards, directly off and/or back to route from bystanders, passersby or commercial transportation ONLY . A racer may not contact friends or family (private parties) living along the route for direct assistance.

P.S.: This rules have been extracted, modified and adapted to our needs from the regulation of the Grand Divide Mountain Bike Route (GDMBR)