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Bicycling Science, Third Edition
Released this April, David Gordon Wilson's updated Bicycling Science fills the gap between, on the one hand, shop manuals and training guides, and on the other the contemporary literature on human powered vehicles. Wilson, Professor Emeritus at MIT, navigates physics and physiology to produce a hefty source of insight.
Wilson splits his book into three broad sections -- the biology of human power generation, the physics of turning complicated muscle motions into linear velocity, and radical redesigns of the standard diamond bicycle frame.
The first section explains, among other things, the role of oxygen uptake and distribution, and gives empirical and theoretical backing to some, but not all, of the conventional wisdom surrounding cycling. The curious will find a detailed explanation of why high pedal cadence allows for long-term, low-intensity, high-efficiency power generation. Modifications to the standard choices -- from elliptical chain-wheels to hand-powered cranks -- are analyzed critically.
The second section might be jokingly termed "extreme high school physics." Wilson explains how people intuitively balance and steer on two wheels, and the design of braking systems to avoid flip-over. He gets down-and-dirty in the metallurgical literature to explain the role of metal fatigue in frame failure, and into fluid dynamics to discuss air drag in laminar and turbulent air flows.
Wilson manages to give a sense of how the different demands physics makes on all aspects of bike design cohere into the more-or-less efficient system that we recognize today as the road and mountain bike. Wilson is an innovator, but he has a healthy respect for current designs along with a good deal of skepticism for passing fads such as that for ultralight components.
The final section covers Wilson's love: the radical redesigns of human powered vehicles to enable people to not only cover vast distances or reach high speeds, but also to swim, submarine, fly and even hover or flap on the power -- between 100 and 700 W -- the "NASA standard" man or woman can provide on timescales between hours and seconds.
The text occasionally jumps into a wider historical and social context to provide lighter relief, such as the diagrams that compare cycling's efficiency to other modes of of transportation (cyclists handily undercut a fully loaded diesel commuter train for calories expended per rider.) Wilson is not amused by those who would compare cyclists to dolphins or hawks in terms of efficiency, distance, or speed -- too bad. A brief rant against cars near the end is the exception to the rule of Wilson's professional, honest style.
Bicycling Science can be used as a handbook for the armchair designer of human powered vehicles. Or, if you prefer, as a way to answer the nagging science questions that arise after a thoughtful bike ride. Perhaps its most inspiring use, however, is as a bed-table compendium of stand-alone investigations into what engineers have come up with on a device that has been perfected, again and again, for decades longer than the internal combustion engine.
You can purchase the Bicycling Science, Third Edition from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, carefully read the book review guidelines, then visit the submission page.
Wilson is an innovator, but he has a healthy respect for current designs along with a good deal of skepticism for passing fads such as that for ultralight components.
Hardly a passing fad. People have been drilling their chainrings (and everything else) for as long as there have been hills to climb.
Every day I ride home to the top of my hill I'm glad to be hauling 17 pounds of bike versus 25.
Take a suitably wide piece of paper. Lay it down on a carpeted floor.
Sit on it, and rock your pelvis forward a little.
Notice the two major depressions? Those are your pelvic bones. That is what you want to contact the seat.
Mark circles on the paper where the depressions are, and take it to a bike shop. Compare it against several seats.
Buy one.
Further info here.
Drill baby drill - on Mars
If I had mod points I'd mod you troll, but surely you must know that in many municipalities cycling on the sidewalk is illegal and cyclists are obligated to ride in the street.
Not only that, but on streets without bike lanes, the law often dictates that a cyclist ride in the middle of the lane.
-carl
. We've got computers, we're tapping phone lines, you know that ain't allowed - Talking Heads, "Life During Wartime"
I mean, unless you've kind of got a death wish. It's about the best way to get hit by a car -- they are far more likely to see you if you are on the road, but when some guy turns directly into you because he didn't see you on the sidewalk...
:)
Oh, and it's usually illegal.
Get a city map, pick some routes that are calmer (i.e., avoid industrial areas, find some back roads, get off the 4 lane commuting routes), and check them out on the weekends. Once you find a good route or two, try it to work. Set a goal of doing it twice a week 6 months a year. You'll never look back.
* Riding in traffic exhaust: there is no good discussion of bike-car interactions. (I recommend Effective Cycling, John Forrester, pub. MIT Press, for lots of statistical and practical information on this subject.) Unfortunately, neither EC or BS cover exhaust; I remember some studies done before gas (petrol) went unleaded in London that showed elevated lead levels in cyclists. Not sure how the trend to LEVs has helped.
* Effeciency of the bicycle design. It is definitely the case that recumbents are more efficient. This is in large part due to wind resistance. In general, designs that allow for continuous motion (e.g., circular motion of pedals) are far better than pumping (discontinuous change of direction), and that's what we've got. Attempts to make the pedal motion more efficient on the upright have not been too successful -- it seems we adapt well and smooth out the minor troubles.
* Bicycle weight: yes, I was wrong to call it a "new" trend to drill out chainwheels and generally obsess over grams. The new trend is perhaps the use of Ti and exotic compounds to lessen weight without sacrificing strength. In any case, even a one pound change in the weight (very large for the obsessives) has little effect on efficiency compared to, e.g., tire pressure, out of alignment parts, chain loss, &c&c. Lance needs it, but Lance has a team of engineers to keep everything else in check! Check it out!
* My comment on the traffic "rant." I am a huge anti-car person when it comes to urban design, and I generally agree with the conclusions of his rant. However, he makes some unsubstantiated claims about traffic flow in order to support his argument, and I just don't think they hold up. It is in stark contrast to the rest of the book, where he is very careful to cite and discuss the evidence for even the most "obvious" assertion.
* Climbing and cycling are totally the geek sports! No question. They are problem solving sports, where you combine smaller syntactical units to form original solutions to constantly changing conditions. (Martial arts fits this description very well, as well.) In cycling, the problem solving happens "offline" and during training, of course, where as martial arts and rock climbing are live. Compiling C versus interpreting LISP, I guess.
Thanks, all who contributed and will contribute! It is fun to see people's opinions, and to discover the number of /bikes.
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