Hammerstone MTB Marathon 2026

Hammerstone is a mountain bike marathon weekend in Valkenburg, Limburg, starting and finishing at the Shimano Experience Center. Held on an October weekend, it continues the former Bart Brentjens Challenge under a new name. The main event is a mountain bike marathon, complemented by tours, clinics, a bike expo, and live podcasts, offering activities for spectators and non-elite riders alongside the races. The marathon also hosts the Dutch Championship XCM, where participants compete for the national jersey. Its UCI C2 status attracts international riders seeking world ranking points. Recreational participants follow the same route as the professionals, encountering technical and physical challenges that elevate it beyond a casual tour. Former Olympic champion Bart Brentjens, the namesake of the original event, remains involved as an ambassador. The Next Bart Brentjens Trophy introduces a youth and talent-development component, aligning with the organizer's commitment to supporting grassroots mountain biking alongside elite competition.