The forests around urban centers are vulnerable to deforestation due to climate change and high societal pressure for recreation. Vienna and Zurich, with populations of approximately two million and 500,000, respectively, exemplify these issues. Both cities are growing, tourism is increasing and forest managers have struggled over recreational infrastructures. Higher urbanization has led to overcrowded urban forest areas and conflicts between the ecosystem services they provide. Mountain biking has developed rapidly in recent years, and the related urban pressure is high.
While some solutions have been found, the question remains as to how sustainable these solutions are in terms of stability and resistance to future challenges. This study investigates the struggles related to the recreational use of urban forests, focusing on illegal mountain bike trails and the response to emerging societal demands from both stakeholders and decision-makers. Using Vienna and Zurich's forests as examples, the research first traces the struggles and related negotiations for the legalization of bike trails back to their origins. Second, it explores the solutions found, and third, it assesses the changes and resulting future demands. Data sources include documents and semi-structured interviews with key actors involved, including bikers and forest managers. Our consideration of bikers and forest managers shows differences and commonalities in actor compositions, planning strategies and outcomes. The most decisive factor for infrastructure installments is organization of pressure from interest groups to influence change. However, the financial solutions require better alignment. It appears questionable whether the trails in their current state can respond to and fulfill growing demands and adapt to current technical innovation in the sports sector. The results provide insights for future efforts on how to govern and manage increasing pressure from urban populations on sports activities within nearby forest areas.