What is CdA?
CdA (coefficient of drag x area) is the major component of aero drag that is typically calculated in the wind tunnel or with velodrome testing. As a rider goes faster the drag force related to pushing the bike through the air grows exponentially, so the lower your CdA the easier it is to cut through the wind. At some point there is a trade off between getting more aerodynamic and producing power. Typical CdA number ranges that should be expected are:
.21 - .23 (World Class Time Trialist)
.23 - .25 (Top End Triathlete)
.25 - .29 (High/Mid Pack Triathlete)
.30 - .35 (Road Racing/Relaxed Position)
.35 - .45 (Climbing / Comfort Position)