In this paper, an experimental validation of some modelling aspects of an uncontrolled bicycle is presented. In numerical models, many physical aspects of the real bicycle are considered negligible, such as the flexibility of the frame and wheels, play in the bearings, and precise tire characteristics. The admissibility of these assumptions has been checked by comparing experimental results with numerical simulation results. The numerical simulations were performed on a three-degree-of-freedom benchmarked bicycle model. For the validation we considered the linearized equations of motion for small perturbations of the upright steady forward motion. The most dubious assumption that was validated in this model was the replacement of the tires by knife-edge wheels rolling without slipping (non-holonomic constraints). The experimental system consisted of an instrumented bicycle without rider. Sensors were present for measuring the roll rate, yaw rate, steering angle, and rear wheel rotation. Measurements were recorded for the case in which the bicycle coasted freely on a level surface. From these measured data, eigenvalues were extracted by means of curve fitting. These eigenvalues were then compared with the results from the linearized equations of motion of the model. As a result, the model appeared to be fairly accurate for the low-speed low-frequency behaviour.@en

In this paper, an experimental validation of the lateral dynamics of a bicycle running on a treadmill is presented. From a theoretical point of view, bicycling straight ahead on a treadmill with constant belt velocity should be identical to bicycling on flat level ground with constant forward speed. However, two major differences remain: first, stiffnesses of the contact of the tire with the belt compared to the contact on flat level ground; second, the belt velocity is fixed with respect to the world, irrespective of the change in heading of the bicycle on the treadmill. The admissibility of these two differences is checked by comparing experimental results with numerical simulation results. The numerical simulations are performed on a three-degree-of-freedom benchmarked bicycle model [1]. For the validation we consider the linearized equations of motion for small perturbations of the upright steady forward motion. This model has been validated experimentally in a previous work [2]. The experimental system consists of an instrumented bicycle without a rider on a large treadmill. Sensors are present for measuring the roll rate, yaw rate, steering angle, and rear wheel rotation. Measurements are recorded for the case in which the laterally perturbed bicycle coasts freely on the treadmill. From these measured data, eigenvalues are extracted by means of curve fitting. These eigenvalues are then compared with the results from the linearized equations of motion of the model. As a result, the model appeared to be accurate within the normal bicycling speed range, and in particular the transition from stable to unstable weave motion was very well predicted.@en

A novel approach to bicycle design for handling qualities is presented. The design method is introduced through a case study in which a new front-wheel drive recumbent bicycle is developed. Since there exists no proper definition nor assessment for bicycle handling qualities, design process is based on comparing the uncontrolled dynamics of the new concepts to an existing design, known to handle well. A prototype was built and road test were conducted to compare the handling before being taken into production. The new design shows comparable handling.@en

This paper gives an overview on handling aspects in bicycle and motorcycle control, from both theoretical and experimental points of view. Parallels are drawn with the literature on aircraft handling. The paper concludes with the open ends and promising directions for future work in the field of handling and control of single track vehicles.@en

A method is presented to estimate and measure the geometry, mass, centers of mass and the moments of inertia of a typical bicycle and rider. The results are presented in a format for ease of use with the benchmark bicycle model [1 ]. Example numerical data is also presented for a typical male rider and city bicycle.@en

The purpose of this study is to identify human control actions in normal bicycling. The task under study is the stabilization of the mostly unstable lateral motion of the bicycle-rider system. This is done by visual observation of the rider and measuring the vehicle motions. The observations show that very little upper-body lean occurs and that stabilization is done by steering control actions only. However, at very low forward speed a second control is introduced to the system: knee movement. Moreover, all control actions are performed at the pedaling frequency, whilst the amplitude of the steering motion increases rapidly with decreasing forward speed.@en

The bicycle is an intriguing machine as it is laterally unstable at low speed and stable, or easy to stabilize, at high speed. During the last decade a revival in the research on dynamics and control of bicycles has taken place [1]. Most studies use the so-called Whipple [2] model of a bicycle. In this model a rigid rider is rigidly connected to the rear frame. However, from experience it is known that some form of control is required to stabilize the bicycle and/or carry out tracking operations. This control is either carried out by steering or by performing some sort of upper body motions. Note that in both cases the system is underactuated. The precise control used by the rider is still under study [3]. This paper addresses the question whether the underactuated bicycle is controllable by only steering or upper body motion in the forward speed range of 0 to 36 km/h. Whipple-like models are studied with either steering or upper body control. It is shown that at certain specific forward speeds some modes are uncontrollable. However, either the forward speed is extremely low or the uncontrollable modes are all stable modes and are therefore of no concern to the rider.@en