'Cyclists Are Now Obsessed With Aerodynamics. But Nothing Beats the Magic of a Superlight Road Bike,' this from a Cervélo R5 review but, I think it applies to me cuz... my average mph is not high (darn it) but... I keep using it as a metric and try to increase it. But then, there's the rub- if I put on aero bars and tucked into an efficient wind-cheating position, I'd increase my avg. mph. Used to have'm and, thinking about going back to it... e.g., there if you need it!