Parametric finite element analysis of steel bicycle frames: The influence of tube selection on frame stiffness

Abstract

This paper presents a parametric Finite Element model of road bicycle frames using beam elements with varying tube profiles. A range of existing frame geometries were subject to various in plane and out of plane loading conditions to examine the influence of tube profiles (as published by the Reynolds, Columbus and Tange manufacturers) on the lateral stiffness and vertical compliance of the frames. This was an extension of previous work which characterised the influence of overall frame geometries (tube lengths and angles) on the stiffness characteristics of frames. For a subset range of frame sizes (with seat tube lengths varying from 490-630mm), parameters were used to define dimensions for circular tube profile shapes, varying wall thicknesses associated with butted tubes. In this paper only steel tubing was considered in order to isolate and focus in detail on the influence of the tube profile geometries on the stiffness characteristics of the frames for a single material. Further work is required to validate this model using a frame stiffness jig and to characterise the influence of material choice on the stiffness and strength characteristics for steel, aluminium and titanium frames using commercially available tubesets and their published stiffness and strength values.