A bicycle and light assembly has wheels, a frame support by the wheels, a bike light supported by the frame, and a mounting system coupling the bike light to the frame. The mounting system includes a socket secured to one of the frame and the bike light, a post secured to the other of the frame and the bike light, and a releasable securing mechanism that secures the post in the socket. The mounting system can further include a mounting bracket coupling the post to the frame, wherein the mounting bracket facilitates rotational adjustment of the post about the post axis. The releasable securing mechanism can include a detent member positioned in a side opening of the socket and in engagement with a recess in the socket to secure the rotational orientation of the post in the socket.