Vertical and Longitudinal Characteristics of a Bicycle Tire
35th Annual Meeting and Conference on Tire Science and Technology
Akron (Ohio), USA
September 13th -14th 2016
Electric Bicycles (EBs) have undergone a real boom in recent years and represent an important part in the area of sustainable mobility. In addition to assisting the driver while accelerating the bicycle, the available electrical energy on EBs also offers the possibility to deploy electronically controlled braking functions to increase safety during critical braking maneuvers. The innovative Braking Dynamics Assistance system (BDA) for bicycles with hydraulic brakes addresses the two major critical braking situations for single-track vehicles: front wheel lockup and nose over (falling over the handlebars).
An essential and crucial prerequisite for the model based development of the BDA braking functions is a thorough understanding of tire effects on braking dynamics. To date there are only very few scientific studies concerning bicycle tire characteristics. Thus test runs on a inner drum tire test bench have been performed to measure vertical and longitudinal characteristics of a typical trekking bicycle tire. This paper presents the main findings such as vertical stiffness and contact patch geometry depending on wheel load and inflation pressure as well as characteristic curves of the longitudinal force depending on slip with variation of road condition, wheel load, speed, and inflation pressure. Based on these valuable insights, further improvements are proposed and an outlook on the next steps of the BDA development is given.