An airflow shaping enclosure is mounted to the rear of a cyclist riding a bicycle. The airflow shaping enclosure is wide at its front and tapers toward its rear, maintaining and shaping airflow streamlines behind the cyclist. The forward section of the airflow shaping enclosure is shaped to match the rear of the cyclist and to fill space behind the cyclist's buttocks, back, and calves. The rear section of the airflow shaping enclosure is shaped to form a streamlined extension of the cyclist's body. The airflow shaping enclosure fore-aft and height locations are adjustable to minimize the gap between the airflow shaping enclosure and the cyclist's buttocks, back, and thighs. The airflow shaping enclosure is configured to carry luggage.