12/24 MTB Challenge Comunidad de Madrid

The 12/24 MTB Challenge Comunidad de Madrid is an endurance mountain bike event held in Manzanares el Real, at the foot of the Sierra de Guadarrama in the Madrid region of Spain. The 2026 edition is scheduled for 13 June and is run as a lap-based race on an 8.24 km circuit, with riders competing solo or in 2- or 4-person relay teams over 6, 12 or 24 hours. Categories are open to MTB, gravel and (non-competitive) e-bikes, and the event also serves as the Madrid Regional Endurance Championship.