Science

Analytic Cycling
Provides technical methods for evaluating and estimating cycling performance and parameters.
http://www.analyticcycling.com/

Bicycle Gearing
Whole lotta gearing going on. Personal home page of a gearing tekkie. Useful lists, large-scale charts and graphs and good explanations.
http://www.geocities.com/SiliconValley/Port/2945/Gears/Gears.html

Bike Think
Gary Houchin-Miller shares his thoughts on technical topics which examine the fundamentals of bicycle performance. Links to lots of additional information as well.
http://www.bikethink.com/

Cycling Science - Summer 1996 - What Determines The Optimal Cadence?
Article about determining the optimal cadence from cycling science.
http://www2.bsn.de/Cycling/articles/cadence.html

Science of Cycling
The Exploratorium in San Francisco answers questions about cycling.
http://www.exploratorium.edu/cycling/

Spoke Length Calculator
Calculates the correct spoke length for any combination of spoke and rim.
http://www.geocities.com/d_halem/wheel/wheel.html