Hammerstone 2026

Hammerstone is a three-day mountain bike and gravel event in October, beginning and ending at the Shimano Experience Center in Valkenburg aan de Geul, Limburg. It unites the former Bart Brentjens Challenge and Bokkebaggertocht under a single banner, featuring short touring rides on Saturday and a marathon on Sunday. The competitive aspect now holds UCI status, and the weekend also includes Dutch Championship races. The route utilizes Limburg's off-road terrain, with a new course previewed through key sections chosen by Bart Brentjens. Brentjens has been involved with the event for almost 20 years and continues to influence how riders approach it, offering guidance on equipment, nutrition, and riding position. Touring participants have the option for extended distances, while the overall weekend incorporates an expo, workshops, podcasts, and a festival atmosphere for mountain bikers surrounding the races.