Generally, sociotechnical change requires that agency is exercised across multiple, connected levels or contexts. Yet there is very little work in the sociotechnical sustainability transitions literature that theorises these connections in ways that acknowledge the individual-level processes involved. Here we show how identity theory can connect macro- and micro-levels of analysis, with identity construction being a social psychological process that is also involved in institutional work. For empirical illustration we use the case of emerging mobility transitions in Berlin, Germany, in particular aspects of institutional work for infrastructural change in favor of cycling. The study shows how the construction of a common identity among varied actor groups has been key to a citizen campaign for safe cycling infrastructure. The construction of a socially inclusive identity relating to cycling has been made possible by prioritizing the development of a campaign network comprised of weak ties among stakeholders, rather than a closer-knit network based on a more exclusive group of sporty cyclists. The findings are discussed in the light of both social psychological models and sociotechnical transitions theory. ... mehrThe implications for scaling niche practices for sustainability are considered.