Abstract: A bicycle chainguard having a housing shaped to enclose a bicycle chain and sized to extend about the front sprocket and pass rearwardly to the rear sprocket of a bicycle, at least one lug extending sidewardly from the housing having a shank and a head of larger cross-sectional area than the shank, a clamp having a flexible body sized to wrap around a portion of the bicycle frame adjacent the front sprocket and having opposing ends forming recesses so that the ends may be jointed to form a socket to receive the lug therein, and a clip to mount the housing to the upper rear of the frame. The socket preferably is sized to provide sufficient clearance with said lug to permit relative rotational movement therebetween so that the chainguard may be adjusted to be mounted to a variety of bicycle frames. The ends of the clamp may be secured by a screw and nut.