Objective: The suspended in-wheel motor drive unit (SIWMDU) is a new electromechanical integration method with a drive system that is elastically mounted within the wheel through spring-damper elements. This configuration delivers important benefits, such as extended motor service life and avoidance of negative effects caused by high unsprung mass. However, the implementation of internal suspension not only raises the number of components but also considerably decreases available space within the wheel envelope. These factors greatly elevate the complexity of mechanical architecture designs. Most current studies in the literature emphasize performance analysis and parameter optimization of specific configurations while ignoring the underlying logic of configuration selection and the possibility of discovering novel and more optimal design solutions. To fill this gap, this study proposes a systematic method to analyze, enumerate, and evaluate various SIWMDU configurations under a unified methodological framework. Methods: This research introduces a configuration synthesis and evaluation methodology that incorporates morphological analysis, topological modeling, and quantitative assessment using a preference matrix. Initially, a functional requirement table is established based on a detailed analysis of existing SIWMDU architectures, which identifies four essential system-level functions: driving, braking, propulsion, and vibration isolation. Then, the main mechanical components are categorized into two morphological classifications according to the rotational behavior of the motor (inner-rotor vs. outer-rotor), and a morphological matrix is constructed to map functional elements to feasible component forms. Thereafter, a set of topological connectivity diagrams is built to correspond to mechanical interfaces and constraints among components, which enables the systematic and exhaustive generation of valid configuration candidates. Ultimately, three evaluation metrics, namely, suspension space, thermal performance, and upright complexity, are chosen to reflect the core difficulties in an SIWMDU design, and these criteria are utilized in a preference matrix to quantitatively assess and compare the performance of each configuration candidate. Results: Using the proposed methodology, the study specifies a total of 18 feasible configurations (6 inner-rotor-based and 12 outer-rotor-based). Among these configurations, well-documented benchmark designs and previously unidentified new configurations are obtained. A novel configuration is emphasized and analyzed comprehensively. It employs an outer disc brake and thin-section bearings, which eliminates the need for a wheel hub or spokes; this greatly expands the usable internal space. The motor in this configuration is positioned outside the wheel and is connected to the rim through a newly designed suspended coupling, which streamlines the upright structure and offers greater flexibility for suspension layout. Comparative evaluation reveals that this configuration realizes notable enhancements in suspension space utilization, heat dissipation, and upright simplification; thus, it provides a promising solution to the space and packaging limitations of current SIWMDU designs. Conclusions: The results verify that the proposed approach allows structured and exhaustive configuration exploration while enabling rigorous multi-criteria evaluation to recognize optimal mechanical solutions. This study exhibits the value of integrating systematic design methodologies, such as morphological matrices and topological modeling, in the conceptual design and innovation of complex electromechanical systems such as the SIWMDU. The method presented herein not only offers immediate practical value for SIWMDU designers but also launches a methodological foundation that can be extended to other complex mechatronic systems encountering similar integration complexities. By formalizing the configuration synthesis process and proposing quantitative evaluation criteria, this work contributes to filling the gap between abstract design theory and practical engineering implementation in the rapidly evolving field of electric vehicle propulsion systems.