The right way to ride the wrong bike: An exploration of Klein's 'unridable' bicycle.

Professor Richard Klein and his students built a bicycle with a rather interesting feature: no one was able to ride it. A prize was offered. Hundreds of students and cycling enthusiasts attempted it. Years passed, and the prize money grew. Klein's rear-steered bicycle became a canonical example...

Full description

Saved in:
Bibliographic Details
Main Author: B D Coller
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0315769
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1841555619854680064
author B D Coller
author_facet B D Coller
author_sort B D Coller
collection DOAJ
description Professor Richard Klein and his students built a bicycle with a rather interesting feature: no one was able to ride it. A prize was offered. Hundreds of students and cycling enthusiasts attempted it. Years passed, and the prize money grew. Klein's rear-steered bicycle became a canonical example of how non-minimum phase systems can be difficult and sometimes nearly impossible to control. It has been lauded as a particularly effective educational example in which students can experience the loss of controllability in a seemingly simple, albeit unorthodox bicycle. The primary result of the work reported here is a demonstration that it is possible for a human of modest athletic ability to ride Klein's unridable bicycle, to keep it balanced, and to control its direction of travel. There is a secret to riding Klein's rear-steer bicycle. The secret is revealed through an exploration of the dynamics and control of the bike that contains three elements: (1) modeling the physics of the actively steered bicycle as an inverted pendulum riding atop a carriage; (2) recognizing that the steer kinematics leads to competing physical mechanisms which an aspiring rider might exploit; and (3) examining limitations of controllability and stabilizability of the system from a state space perspective. From this vantage point, one can devise a novel strategy, based on a component of lateral acceleration that dominates at low speed, for riding the so-called "unridable" bike and solving Klein's puzzle. The work adds a new chapter on the dynamics and control of the rear-steered bicycle, a problem of academic interest.
format Article
id doaj-art-9f099e9bd8f34e8389b9778c9a96bd42
institution Kabale University
issn 1932-6203
language English
publishDate 2025-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-9f099e9bd8f34e8389b9778c9a96bd422025-01-08T05:31:57ZengPublic Library of Science (PLoS)PLoS ONE1932-62032025-01-01201e031576910.1371/journal.pone.0315769The right way to ride the wrong bike: An exploration of Klein's 'unridable' bicycle.B D CollerProfessor Richard Klein and his students built a bicycle with a rather interesting feature: no one was able to ride it. A prize was offered. Hundreds of students and cycling enthusiasts attempted it. Years passed, and the prize money grew. Klein's rear-steered bicycle became a canonical example of how non-minimum phase systems can be difficult and sometimes nearly impossible to control. It has been lauded as a particularly effective educational example in which students can experience the loss of controllability in a seemingly simple, albeit unorthodox bicycle. The primary result of the work reported here is a demonstration that it is possible for a human of modest athletic ability to ride Klein's unridable bicycle, to keep it balanced, and to control its direction of travel. There is a secret to riding Klein's rear-steer bicycle. The secret is revealed through an exploration of the dynamics and control of the bike that contains three elements: (1) modeling the physics of the actively steered bicycle as an inverted pendulum riding atop a carriage; (2) recognizing that the steer kinematics leads to competing physical mechanisms which an aspiring rider might exploit; and (3) examining limitations of controllability and stabilizability of the system from a state space perspective. From this vantage point, one can devise a novel strategy, based on a component of lateral acceleration that dominates at low speed, for riding the so-called "unridable" bike and solving Klein's puzzle. The work adds a new chapter on the dynamics and control of the rear-steered bicycle, a problem of academic interest.https://doi.org/10.1371/journal.pone.0315769
spellingShingle B D Coller
The right way to ride the wrong bike: An exploration of Klein's 'unridable' bicycle.
PLoS ONE
title The right way to ride the wrong bike: An exploration of Klein's 'unridable' bicycle.
title_full The right way to ride the wrong bike: An exploration of Klein's 'unridable' bicycle.
title_fullStr The right way to ride the wrong bike: An exploration of Klein's 'unridable' bicycle.
title_full_unstemmed The right way to ride the wrong bike: An exploration of Klein's 'unridable' bicycle.
title_short The right way to ride the wrong bike: An exploration of Klein's 'unridable' bicycle.
title_sort right way to ride the wrong bike an exploration of klein s unridable bicycle
url https://doi.org/10.1371/journal.pone.0315769
work_keys_str_mv AT bdcoller therightwaytoridethewrongbikeanexplorationofkleinsunridablebicycle
AT bdcoller rightwaytoridethewrongbikeanexplorationofkleinsunridablebicycle