The logistical requirements of moving goods and people within the urban environment are used to justify the use of motorised transport, within the domestic as well as the commercial realm. Serious environmental and social problems are linked to this reliance on carbon-intensive forms of mobility. Researchers and policy makers have turned their attention to alternatives to petroleum-based modes of urban travel and goods delivery. A new (old) cargo-capable technology, the cargo bike is resurgent in some, predominantly European, cities and has been the focus of European Union funded studies into its viability particularly within the urban commercial freight logistics chain. This thesis makes an original contribution to current debate on promoting cycling by examining the ability of the cargo bike to meet urban load-carrying needs. This is achieved by extending consideration, from a social practice theoretical perspective to the freight function of domestic travel. This contribution is achieved in four main ways. Firstly, I extend study of cargo-cycling beyond the acclaimed cycling cities of Europe, to the US city of Portland, Oregon and to Christchurch, New Zealand. I focus attention on cities which have, by Anglophone but not European standards, relatively high cycling modal share, but until recent years only limited cargo bike availability. Secondly, by attending to domestic load-carrying, the relationship between transporting children, shopping, and other domestic goods, and achieving other daily mobility needs - the complexities of domestic logistical practices - are uncovered. Thirdly, I examine the nuanced relationship between cycling and driving in achieving cargo-capable mobility. Fourthly, by approaching the study of cargo-cycling from a practice-theoretical perspective, which challenges the dominance of policy formulations which rely on technical innovation and/or individual behaviour change, I focus on what people actually do, and examine the implications of a social practice theoretical approach. By combining research techniques of empirical investigation with refinement of existing conceptual models, this study contests simplistic, dualistic representations of cycling versus driving. Instead, fluid nuanced relationships are identified, of bifurcation and hybridisation within and between load-carrying practices, impacted by the rhythms and (a)synchronicities of meeting load-carrying need. Complexity rather than the compartmentalisation of the practices which constitute daily life is highlighted. Cargo cycles are found to be uniquely placed in offering a low-cost-in-use decarbonised mode of mobility, which can mesh with combinations of domestic and commercial practices. Access to the practice of cargo-cycling is found to be limited by availability and cost. This research, therefore, calls for innovation which facilitates access to the relatively environmentally and socially sustainable practice of cargo-cycling, as a low-cost-in-use cargo-capable mode of transport.