Cycling coach, writer, and masters champion Arnie Baker has surveyed many controlled experiments in this article. Baker gives very short summaries of studies in many areas -- nutrition, equipment, training/racing, medicine, psychology, etc.
Sample conclusions are: pacing paid off in a 20 kilometer bike time trial, clipless pedals do not offer a physiological advantage, a fifty percent taper a week before a race is beneficial. Still, the bottom line is that the experimental differences tend to be marginal -- training is still the key.
Baker has written many other books and articles, available at his Web site.
Could we learn by each of us conducting a one-person experiments and reported our results on the Net?