Design Analysis of an Adjustable Road Bicycle Stem Based on Ergonomics and Biomechanics
DOI:
https://doi.org/10.51747/energy.v16i2.p459-473Keywords:
Adjustable stem, Bicycle ergonomics, Biomechanics, Motion captureAbstract
Road bicycles are designed to achieve aerodynamic efficiency through a forward-leaning riding posture. Although this position can improve cycling performance, it may also increase biomechanical loading and the risk of musculoskeletal complaints when it is not aligned with the rider’s anthropometric characteristics. The limited adjustability of conventional bicycle stems further restricts riders from achieving a more ergonomic riding position. This study investigated the ergonomic and biomechanical performance of an adjustable road bicycle stem developed to provide greater flexibility in handlebar positioning. A comparative experimental design was employed involving 30 road cyclists, with measurements conducted before using the standard stem and after using the adjustable stem prototype. Riding posture was assessed using motion capture to determine trunk flexion angle, while biomechanical loading was evaluated by calculating trunk moment. Ergonomic performance was assessed using the SNI 9011 questionnaire for musculoskeletal complaints. The adjustable stem increased the mean trunk flexion angle from 30.73° to 52.90° and reduced the average trunk moment from 193.94 Nm to 136.13 Nm. Participants also reported lower musculoskeletal complaint risk following use of the prototype. These findings suggest that the adjustable stem offers a more adaptable riding position and contributes to improved ergonomic performance by reducing biomechanical loading. The study provides evidence that incorporating ergonomic and biomechanical considerations into bicycle stem design can support the development of road bicycle components that better accommodate variations in rider characteristics.
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