| The road bicycle frame has existed in its present geometry since the turn of the Twentieth Century. Since then there have been academic and industrial research activities focused on its design. There were peaks in this research during the early Twentieth Century and, more recently, during the 1970's and 1980's. Since the 1980's most of the industrial research has been proprietary and detailed results are not generally released. Academic research continues but there are not a large number of published papers.The design and analysis of the road bicycle frame is described in this thesis. The goal of this research was to provide a set of design tools and guidelines to the road bicycle frame designer and builder. The specific objectives were: (1) To develop simple computational models for evaluating the static loads, stresses and deflections in the frame, focusing on the bottom bracket region. (2) To develop experimental methods for measuring the stiffness of the bicycle frame including the design and fabrication of test fixtures. (3) To validate the computational model through testing. (4) To develop a method for fatigue testing a bicycle frame focusing on the junction of the bottom bracket and chain stays and to analyze several failures in that region. (5) To investigate the correlation between frame stiffness and vibration transmitted to the rider through static and dynamic testing. This research determined: (1) Simple computational models can be useful for evaluating loads, stresses and deflections in the road bicycle frame. The builder can use these models to help in the selection of frame tubing and fabrication methods. (2) Fatigue failure in the bottom bracket region of the frame is a major problem that needs to be considered during the design and fabrication of the frame. (3) There is minimal correlation between frame stiffness and vibration transmitted to the rider, which indicates the complete system needs to be considered to determine rider comfort. |
