For nearly 150 years, that two-wheeled conundrum, the bicycle, has baffled scientists attempting to answer the question: how can a moving bicycle remain so stable, all by itself? Researchers from the Delft University of Technology, in the Netherlands, working with British colleagues from the University of Nottingham and American engineers from Cornell University, now believe they have at last discovered its secret.
‘Bicycle manufacturers have never been able to say exactly how a bicycle works,’ says Dr Arend Schwab of the Faculty of Mechanical, Maritime and Materials Engineering. ‘They have always had to refine their designs purely through experimentation. In our model, they can enter into the computer all of the various factors that influence the stability and handling of their bicycle. The model then calculates how the bicycle will react at specific speeds.’ Recently the model was published in the science journal Proceedings
of the Royal Society, Series A.
|After 150 years the bicycle has given up its secret.
Fellow researcher and off-road cycling enthusiast Jodi Kooijman states, ‘The bike’s speed should be between fourteen and twenty seven kilometers per hour. At those speeds, the bicycle is inherently stable. If it goes faster, it will wobble less, but if you then push it sideways it will lean over to one side until it topples. The data match our model predictions exactly.’
The bicycle industry has expressed interest in the group’s findings because the model is capable of showing whether a certain design will result in a jittery ride, or a more stable one suitable for seniors. Rob van Regenmortel, head of product development for Dutch cycle manufacturers Batavus explains, ‘In designing our bicycles, for years we have worked with three parameters: The overall geometry, the distance between the axles and the angle at which the fork points downwards. These choices were once made by all bicycle makers and have rarely been deviated from because the bicycle appeared to work properly. However, with the new model, we soon hope to be able to design bicycles that are much better orientated toward specific target groups.’
Rob Van Regenmortel intends to join forces with Arend Schwab and Jodi Kooijman on a follow-up project to investigate the human control of the bicycle. The main aim of this research into bicycles is to explore the interaction between machine and rider in order to explain the handling quality of the bicycle. ‘In this way we can, in theory, create a customised bicycle for every rider. Individuals who have trouble maintaining their balance, for example, would then no longer be restricted to a tricycle,’ underlines Rob van Regenmortel.