Originally Posted by
spartanKid
FWIW I don't remember where I saw this, but I think more headset spacers and a flatter stem angle is "more aero" than fewer spacers with a positive rise stem.
You saw it from Specialized.
They came out with a study that it is more aero to have a -17 stem and their 25mm riser than to go with a stem that is angled up (anything less than -17) and flatter bars.