The International Paralympic Committee mandates the development of an evidence-based classification system, which requires a measure of performance. Performance in cross-country sit-skiing is mainly dependent on force generated during the poling phase and is enhanced by trunk flexion–extension movements. Since all sit-skiers have neuromuscular impairment, but different ability to control the trunk, this study aimed to verify if simulated action of poling on an adapted ergometer, together with a cluster analysis, could be used for grouping participants with different impairments according to their performance. On the ergometer, eight male and five female participants performed seven poling cycles at maximal speed, while sitting on personal sit-ski. Based on maximal speed, generated force, cycle characteristics, and trunk kinematics, cluster analysis divided participants into three groups showing good accuracy, sensitivity, and precision. Although a validation of this exploratory study is necessary, skiing on the ergometer could be considered as sport-specific measure of performance and may become an interesting tool in the development of an evidence-based classification system for cross-country sit-skiing.