Micromobility sharing systems gained increasing attention due to their potential to promote sustainable transport and health and environmental benefits. E-cargo bike sharing systems (ECBSS) remain sparsely researched despite their increased sustainability potential, which offers the opportunity to replace car trips for transporting larger items. The current study investigates the acceptance, usage behaviour and contextual influences on using ECBSS. We used living lab data (2022–2024) from the SteigtUM project in a small German town. Participants (N = 78) completed surveys on satisfaction, acceptance and usage behaviour at different stages of their experience with the system. The results demonstrate a high level of satisfaction with the system. Acceptance measures resulted in consistently positive evaluations. Personal innovativeness and behavioural intention were strongly correlated, indicating that usage intention is higher for participants who adopt new technologies quickly. Behavioural usage patterns showed a modal shift from commuting trips in 2022 to shopping-related trips in the following years. Approximately 20–30% of car trips were replaced with the system, reflecting a high potential to contribute to sustainability goals for the investigated user group. Weather conditions had a limited impact on usage. In sum, study results highlight ECBSS as an alternative to reduce motorised transport, especially in smaller cities. Targeted strategies are needed, however, to overcome barriers to adoption and encourage a broader range of potential user groups. Future research should investigate long-term effects and include safety aspects to optimise user experience and acceptance.