To navigate sustainability transitions, firms are often prompted to take an active role in business model innovation. Previous research has shown, however, that when attempting to change business models, incumbent firms frequently face challenges concerning the ambiguity of transition pathways. This paper is an inquiry into this intersection between business model innovation and sustainability transitions. Anchored in three case studies of sustainability-driven, pre-commercial projects of emerging technologies, it reveals how groups of organizations collaborate in time-limited, cross-industry networks, to explore potential business models for anticipated, profound, changes in socio-technical systems. Drawing on these findings, the paper introduces the concept of experimental networks and illustrates how experimental networks can facilitate business model innovation in relation to systemic change. By outlining the constituents of the experimental network concept, the paper contributes to theory by uncovering the interplay of interorganizational collaboration and network level business model innovation. In addition, it reveals how experimental networks constitute one way for incumbents to claim agency with respect to emerging sustainability transitions.