The article discusses what we term urban social formations and expands on prior work that predominantly examines urban 'subcultures' as opposed to the world city paradigm and homogeneous cityscapes. We describe the process of 'subculturalization' through which urban social formations, after they have been marginalized and illegalized, become formalized as subcultures and incorporated into the fabric of consumption and profit making. The article proposes that these ossified moments of crystallized practice are only part of wider rhizomatic territories that remain open fields for urban engagement, inviting fluid urban identities and creative states of becoming. The article concludes by exploring the challenges and opportunities of conceptualizing urban social formations as rhizomes.