The Exploratorium in San Francisco answers questions about cycling.
Provides technical methods for evaluating and estimating cycling performance and parameters.
Discussion of bicycle crank length, pedalling technique, chainring shapes and position on the bike with many references to scientific studies.
Calculates the correct spoke length for any combination of spoke and rim.
Article about determining the optimal cadence from Cycling Science
Whole lotta gearing going on. Personal home page of a gearing tekkie. Useful lists, large-scale charts and graphs and good explanations.