Book Review – Bicycling Science

 

Bicycling Science, 3rd Edition

Everything you wanted to know about the bicycle but were too afraid to ask

By David Gordon Wilson with contributions by Jim Papadopoulos. The MIT Press

 

David Gordon Wilson is British born Professor of Mechanical Engineering Emeritus at the Massachusetts Institute of Technology. He is the co-author of the first two editions of Bicycling Science and was the editor of the journal Human Power from 1994 to 2002.

This book covers the history of human powered vehicles and, as the title suggests, focuses firmly on the bicycle.  It is a text in three parts: I Human Power, II Some Bicycle Physics and III Human-Powered vehicles and machines. Each of which can read independently of the others.

The third edition’s (2004) first section, I, ‘Human Power’ opens with a very informative and myth-dispelling addition to the growing canon covering the history of the bicycle. It is a short but authoritative supplement with diagrams and photographs smartly selected and well positioned to support the text. Rather refreshingly all claims, throughout the book, are fully referenced to allow the reader to delve deeper should they so wish along with a recommended reading suggestion here and there (is that a  ‘get a life, Dey’ I hear from my ever loving partner!) For the more evangelical bicycle advocate there is a brief but telling list of ‘new’ technologies born from bicycle design, engineering and use; leading the way is the mass production and use of ball bearings with the oft-neglected good-roads movement also getting a mention – topical as the latter is today. Chapter one also covers, in sufficient detail for all but the expert, Human Power Generation. This encapsulates bicycle focused physiology (how energy gets to the muscles of a rider), biomechanics (how the muscle produce power at the pedals) and should, the author states, ‘allow the reader to feel qualified to absorb the main conclusions of the research papers in this area.’ It is essentially a well written literature review and I for one felt a little daunted at times but quickly discovered my research reading skills were revving back up to speed. The counter-intuitive description of ‘the timing and direction of foot force, choice of crank length, the effect of saddle height and gear ratio, and where to stand up or ‘bounce’ the upper body’ are all treated in depth and supported by evidence based research, with the tradition of the philosophical ever present.  For the more competitive cyclist there is a very useful treatment covering the measurements of human power output, how to describe pedalling performance quantitatively and a very useful presentation into critical power using power-duration curves along with detailed pedal-force data and graphs. Non-round chainwheels also receive useful coverage, another highly topical debate in the age of Wiggo. There is a closing piece on the thermal effects of cycling. Again one only needs to observe the top riders and teams to see this science trickling in and, not before time, replacing much erroneous traditional methods.  The conclusion to the chapter reads like a British Cycling ‘marginal gains’ to do list and the eight pages of academic references tell you all you need to know about the diligence of the author.

Section II ‘Some Bicycling Physics’ is the where I began my reading. For want of getting carried away, as I often do when physics takes centre stage, I shall be brief.  Building on the power-duration data from the previous chapter the author presents a quantitative treatment of cycling specific physics. Anyone with an interest in physics, a little patience and, most usefully, a head full of positive secondary school memories, will be amply rewarded for their efforts.  The main protagonists are all covered namely propulsive force, air resistance and rolling resistance. The author then takes it a step further; what happens when bumps are encountered – of vital interest to the classics riders out there. The concept of vibration frequencies is simply presented and should allow the reader to filter the engineering and physics from the marketing hype the next time a high-end bike is purchased. A lot of paper is devoted to the relationship between power and speed and this alone makes this book a must-read for anyone venturing into the world of the power meter. Bicycle aerodynamics is covered with the usual simple physics formula, text, graphs and some very eye-catching photographs to emphasise the points and aid the understanding of the concepts – all the while retaining a strong link to the context of the bicycle. Rolling resistance, with a focus on wheels tires and bearings ramps up the physics a wee bit but is well worth devoting time to, especially if, like me, you are considering taking the hand-built wheel route. A brief but detailed design, engineering and physics of braking, in differing weather conditions, brings to a close this very informative and rewarding chapter.

The final section, III, Human-Powered Vehicles and Machines, is where the author diverges from the bicycle as we know it. It is the authors stated aim to ‘… expand your experience, and perhaps to make you want to use, or even to design and make, some interesting human-powered vehicles other than bicycles.’ In it he takes a more utilitarian approach and differentiates between the developed and developing world, all the while suggesting that the more bicycling the better; ‘… Even in large countries, like the United States, over half the daily “person-trips” by automobile are of under 8 km (5 miles), a distance most people can easily cover on a bicycle in most weather conditions.’ This chapter contains varied examples of human-powered tools and of record breaking and other interesting vehicles – other than the standard bicycle. It concludes with a thought-provoking piece on Human-Powered Vehicles in the Future; one for all you light weight junkies, aero wheel obsessives and mono-blade maniacs. The piece on the hydraulic disc brake, coming as does so soon after a brief summary of governing body regulations and incentives, is somewhat prescient. The question hangs in the air, what drives the industry; science and performance or marketing? If it is indeed the latter then we are living in a dark age of delusion.

 

Overview, from the back cover

The bicycle is almost unique among human-powered machines in that it uses human muscles in a near-optimum way. This new edition of the bible of bicycle builders and bicyclists provides just about everything you could want to know about the history of bicycles, how human beings propel them, what makes them go faster, and what keeps them from going even faster. The scientific and engineering information is of interest not only to designers and builders of bicycles and other human-powered vehicles but also to competitive cyclists, bicycle commuters, and recreational cyclists.

The third edition begins with a brief history of bicycles and bicycling that demolishes many widespread myths. This edition includes information on recent experiments and achievements in human-powered transportation, including the “ultimate human- powered vehicle,” in which a supine rider in a streamlined enclosure steers by looking at a television screen connected to a small camera in the nose, reaching speeds of around 80 miles per hour. It contains completely new chapters on aerodynamics, unusual human-powered machines for use on land and in water and air, human physiology, and the future of bicycling. This edition also provides updated information on rolling drag, transmission of power from rider to wheels, braking, heat management, steering and stability, power and speed, and materials. It contains many new illustrations.

Title:
Bicycling Science – Everything you wanted to know about the bicycle but were too afraid to ask 

Author:
David Gordon Wilson    

Published by:
MIT Press; 3rd Revised edition edition

Available in Paperback

Price:
RRP £19.95 (Paperback)