Please provide the equation then. If you can reduce the CdA by whatever means, it will make an exponentially larger difference as the velocity increases. Power consumed by drag is CdA*V^3 blah blah blah.....but, wouldn't the airflow attach to the wheel past a certain speed? Before that the airfoil effect wouldn't be as effective? I know Zipp dimples aim to keep the airflow attached but I would think a certain air velocity would be required for that to actually happen.