Just because you paid $3,000 for your new titanium-and-carbon-fiber ride doesn't mean the bike fits your physique. And having the right-sized cycle can mean the difference between hours of blissful injury-free pedaling and weeks of constant rehab for your clicking knees. Many bike shops now offer a bike-fitting service. But why mess around? Go to the guy who literally invented the concept: Andy Pruitt, director of the Boulder Center for Sports Medicine. At $180 for a "performance" fit or $400 for a three-dimensional cycling analysis, Pruitt or one of his staff will customize your bike to your body's twisted idiosyncrasies. Ride on!