The 6H VTT Château de Courtanvaux is a six-hour mountain bike relay held in the woods and parkland of Château de Courtanvaux, located in Bessé-sur-Braye, Sarthe. Teams cycle from noon into the evening, with two, three, or four participants sharing the effort to complete the maximum number of laps before the time limit expires. The L'Anille Braye triathlon club is the organizer, and timing adheres to FSGT regulations.
The circuit measures approximately five kilometers, featuring about 90 meters of elevation gain per lap. This format involves repeated short-course mountain biking until fatigue becomes a significant factor. While the route is redesigned annually, it consistently remains within the natural terrain of Courtanvaux's park and woods. Team registration is typically limited to 99, though interest can exceed this number. The participant roster often includes a mix of local friend groups and former professional riders like Denis Leproux. Observers can easily follow the relay's progression because of the consistent return to the same loop over the six-hour duration.