An air suspension system for use with vehicles such as motorcycles and bicycles comprises a sealed chamber inside the handlebars and a fluid line that interconnects the chamber with the vehicle's pneumatic shock absorber, typically part of the forks. Preferably, the system includes a control valve in fluid communication with the chamber and disposed at or between the handlebars or at the forks. In the preferred embodiment, the control valve is connected to a port located near the center of the handlebars. The preferred embodiment also includes a manual pressure release valve in communication with the chamber and an oil/air separator and/or check valve configured to generally prevent oil from entering the chamber. The pressure release valve and/or the separator or check valve can be made integral with or separate from the control valve. Handlebar caps or plugs can be used to seal the handlebars.