As most cyclists know, aerodynamics plays a major role in how fast you are on the bike. According to Specialized, upwards of 80% of your pedaling effort is just to overcome wind resistance. And while many of us obsess over our watts/kg number - how much power we can put out per kilogram of bodyweight - another, perhaps easier get, is reducing our aerodynamic drag or CdA, (frontal area coefficient of drag).
You don't need a new frame or deep dish wheels to save lots of watts either. Here’s a few easy areas of power savings, (these are ballpark numbers of course- there are many variables to CdA, like how big that melon on your shoulders is!):
Riding in the drops vs hoods: 20-50 watts
Aero helmet: 10 watts
Shaved legs: 20 watts
Skinsuit: 20 watts
Facial hair: No difference
Watch this excellent Ask a Cycling Coach episode below to hear more about wind tunnel testing and CdA at Specialized’s facility in Morgan Hill, CA. Most wind tunnels are designed for cars, but their tunnel is one of the few in the world optimized for cycling.