Bicycle Research Projects at Cornell

Bicycle research began in 1985 when Jim Papadopoulos came to Cornell to work with Andy Ruina (or visa versa). Undergraduate projects in the past have involved the application of constraints to pedals, making a geared unicycle, designing a new suspension, measuring the efficiency of a bicycle transmission, designing a constrained pedal, tests of stability, automatic wheel trueing, tests of what people can percieve, measurement of the effect of inertia on pedaling efficiency, etc. But the bike research has been on a back burner for over a decade but with a recent revival. Starting in 2002-3 with the visit of Arend Schwab from Delft, collaborating with graduate student Andrew Dressel, the stability research is being reviewed and advanced. Arend continues this work in Holland (see Arend's www page).

Here are some things to read. With some trouble reports from the above projects are available. Here is what we think is the definitive paper, in 2004 conference form, on the linearized equations of motion of a bicycle. This will be expanded into a paper shortly.

Scott Hand's thesis (200 pages,12.5 Meg, PDF) on the stability of an uncontrolled bicycle is thorough and has the only relatively complete survey of papers on bicycle stability. He was advised by Jim Papadopoulos and Andy Ruina.

Here is Jim Papadopoulos's summary of the bicycle dynamics equations and what he knew about them: paper2

Here are other bicycle articles, mostly by Jim Papadopoulos, mostly incomplete. There is some contribution from Scott Hand, John Olson, and Andy Ruina.

Forces in Bicycle Pedaling.
Bicycle dynamics experiments you can do.
Comments on L'Hennaff quasi-static dynamics paper.
Popular paper on Dynamics with supplementary material.
Scaling laws (and 100 year history of bicycle dynamics equations from Hand's thesis).
One step frame alignment.
Incomplete paper1, paper3 on bicycle dynamics.

Contact Jim Papadopoulos directly at     

Here is an external site with various bicycle related links:   Some ideas for bike projects .
Some more external links:

Here is a bike stability demonstration video. Its message is somewhat subtle. The fist part is of a rolling wheel. The observable asymptotic stability of the wheel is not reflected in the equations of motion of a rolling disk or toroid. So it must follow from various non-point-contact and friction effects. The more-clearly-observable assymptotic stability of the bicycle, a random bicycle lying around that was aligned so avoid a bias to one side or the other, is reflected in the equations of motion of an ideal conservative bicycle (with disk wheels and point contact).

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