Research in sustainability transitions increasingly acknowledges that the structural characteristics of socio-technical systems differ. However, little attention has been paid to the specific transition dynamics that can result from this structural variation. In response, this paper develops a framework for studying transition dynamics that takes the structural characteristics of socio-technical systems and their influence on agency into account. We introduce the concept contestation axis to highlight alternative potential interfaces between functional solutions in a socio-technical system. We argue that considerable agency and frictions between actors can play out at other axes than between established regimes and emerging niches. Our conceptual framework is applied to a case study in the waste sector. We explore how the growing influence of the circular economy triggers misalignment between multiple socio-technical configurations in the Danish waste sector. In the case, we zoom in on three actual frictions that have manifested along different contestation axes.