The present invention is directed to a garment clamping device for bicycles, motor bikes or other transportation vehicles upon which a flag or banner may be secured and displayed. The clamping device comprises two generally rectangular shaped halves which are joined together by a hinge strap mechanism. Each half has at least one aperture and at least one corresponding mounting stud for clamping the two halves together. Further, each half has at least one barb and at least one corresponding aperture located on the other half for holding and supporting a display flag after the apparatus is clamped closed. Extending outwardly from the bottom of one half is a shaft and a clamping means for securing the apparatus to a tubular member or handlebar of a bike. In operation, a garment is placed on one of the halves and the device is manipulated into a closed position such that the mounting stud, barbs, and respective apertures are engaged. Thereafter, the clamping means is positioned around a tubular member of a bicycle, such as a handlebar, and secured in a closed position.