On the same motorcycle at the same speed, a posture change exposes the rider more to airflow and increases effective frontal area without improving the drag coefficient. What happens to air resistance?

Correct answer

aerodynamic drag is greater.

It increases under those conditions. Aerodynamic drag depends on relative air speed, design and frontal area, not merely whether the handlebar is high or far away. It can raise required power and consumption. Nor does it eliminate mirror blind spots. Adjust controls only as permitted and keep a position that allows safe control.