The Science of Cycling
 

http://www.exploratorium.edu/cycling/index.html

Some may find this link informative. The more experienced rider may find the content over-simplified. Given the number of questions from new riders about how does this or that work, I thought this might be of some benefit.

The link provides a reasonable amount of good information on 'the science of cycling'. Too bad the 'human power' section is so brief, and the overall focus is on cycling as sport. This web site would be much, much better if it had a least some rudimentary information on cycliing for transportation, and not just for sport.

If you want the gory math and physics details, read Performance Cycling: A Scientific Way to Improve Your Cycling Performance by Stuart Baird

It is presented in a light hearted way while giving you the details behind common and uncommon riding practices.

Thanks rockymtn girl for posting this link. I found this site very interesting.

I have Bicycling Science, Second Edition
by Frank Rowland Whitt, David Gordon Wilson, James C. McCullagh (Designer). It's a great book if you're a geek like me who really enjoys getting deep into the nitty-gritty.