User-Centered Concept Development for Stability: From User Insights to Early Prototyping : A Study on Stationary Instability in Bicycle Trailer Systems

Sammanfattning

Purpose – The increasing use of Bicycle Trailer Systems for transporting children has highlighted challenges related to stability during stationary situations such as loading and unloading. Existing solutions are often integrated into specific product models and primarily address dynamic riding conditions, leaving stationary interaction less explored. At the same time, a lack of alignment between product design and actual user needs may lead to reduced usability. Therefore, the purpose of this thesis is to explore how User-Centered Design can support the development of a cross-model compatible solution to improve stability during stationary loading and unloading in Bicycle Trailer Systems. Method – The thesis combines principles from User-Centered Design with a structured product development process based on the Double Diamond Framework. A mixed methods approach was applied, including literature review, market research, a questionnaire, semi-structured interviews, and observational studies. The collected data was analyzed through functional analysis, product specification, and concept generation, followed by concept evaluation using a weighted decision matrix, user-informed assessment, and early prototyping. Findings – The findings indicate that instability is primarily a system-level issue related to insufficient support from the bicycle rather than the trailer itself. Key contributing factors include load shifts during user interaction, limited support conditions, and environmental influences such as uneven terrain. Two concepts were developed to address these challenges, focusing on improving stability, usability, safety, and cross-model compatibility. The evaluation resulted in one concept being chosen for early prototyping, but further development and physical testing are required to validate performance and reduce identified risks.