Originally Posted by
sosojeffcc
just checked on wheelbuilder.com for HED belgium, and again, nothing about being aero.
That being said tho, the Flo 30's do look like a mighty good option, especially with that toroidal shape much like the zipp 101's.
From Wheelbuilder.com:
HED named their C2 series rims after the lower coefficient of rolling resistance (Crr) and higher aerodynamics (Cda) provided by the 23mm wide rims. With 23c tires, the C2 rim creates a constant tire profile, rather than getting pinched into the rim. The overall ride quality is improved and the result is tubular-like ride quality from a clincher tire. The smooth transition from the tire to the edge of the rim allows laminar air flow and lower aerodynamic drag.