See the following for Hammer Strength HD Air Bike Fan Guard Adjustment Instructions
How to Adjust AirGuard
The fan offers cooling to the rider and the AirGuard adjusts the amount of airflow. Adjust air flow as needed.
To adjust airflow, grab AirGuard handle (1) and adjust up or down. AirGuard can be adjusted to six locations.
See the Hammer Strength HD Air Bike Owner's Manual for more information