An axle assembly for removably retaining a wheel on a two wheeled vehicle, such as a bicycle or motorcycle, which axle assembly comprises: an axle shaft comprising a bolt end and a lever end; a lever-operated cam assembly mounted on said lever end, said cam assembly comprising: a cam follower shaft coaxially located substantially within and attached to said axle shaft at a location proximate the lever end, wherein said cam follower shaft does not extend the full length of said axle shaft, the cam follower shaft having external threads at a first end and a transverse bore at a second end opposite said first end for receiving a cam shaft, said cam follower shaft attached proximate said first end to the axle shaft by said external threads that mate with internal threads inside the axle shaft, and wherein said cam follower shaft is held in rotational position by a pin which penetrates a wall of said axle shaft at two points opposite one another and each at approximately 90 degrees to a longitudinal axis of the axle shaft; a cam housing retained on said cam follower shaft by the cam shaft which passes through said transverse bore, a cam surface of the cam shaft enclosed by the cam follower shaft within the cam housing; a lever, which lever is rotatable between an open position in which said axle assembly is readily removable from said vehicle, and a closed position in which said axle assembly is retained on said vehicle, rotation of said lever toward said open position effecting a corresponding rotation of said cam shaft which causes said cam housing to move axially away from said axle shaft, and rotation of said lever toward said closed position effecting a corresponding rotation of said cam shaft which causes said cam housing to move axially toward said axle shaft; and wherein said cam assembly comprises a lever stop that ensures said lever has an angle of maximum rotation from said closed position that is less than 180o. an axle shaft comprising a bolt end and a lever end; a lever-operated cam assembly mounted on said lever end, said cam assembly comprising: a cam follower shaft coaxially located substantially within and attached to said axle shaft at a location proximate the lever end, wherein said cam follower shaft does not extend the full length of said axle shaft, the cam follower shaft having external threads at a first end and a transverse bore at a second end opposite said first end for receiving a cam shaft, said cam follower shaft attached proximate said first end to the axle shaft by said external threads that mate with internal threads inside the axle shaft, and wherein said cam follower shaft is held in rotational position by a pin which penetrates a wall of said axle shaft at two points opposite one another and each at approximately 90 degrees to a longitudinal axis of the axle shaft; a cam housing retained on said cam follower shaft by the cam shaft which passes through said transverse bore, a cam surface of the cam shaft enclosed by the cam follower shaft within the cam housing; a cam follower shaft coaxially located substantially within and attached to said axle shaft at a location proximate the lever end, wherein said cam follower shaft does not extend the full length of said axle shaft, the cam follower shaft having external threads at a first end and a transverse bore at a second end opposite said first end for receiving a cam shaft, said cam follower shaft attached proximate said first end to the axle shaft by said external threads that mate with internal threads inside the axle shaft, and wherein said cam follower shaft is held in rotational position by a pin which penetrates a wall of said axle shaft at two points opposite one another and each at approximately 90 degrees to a longitudinal axis of the axle shaft; a cam housing retained on said cam follower shaft by the cam shaft which passes through said transverse bore, a cam surface of the cam shaft enclosed by the cam follower shaft within the cam housing; a lever, which lever is rotatable between an open position in which said axle assembly is readily removable from said vehicle, and a closed position in which said axle assembly is retained on said vehicle, rotation of said lever toward said open position effecting a corresponding rotation of said cam shaft which causes said cam housing to move axially away from said axle shaft, and rotation of said lever toward said closed position effecting a corresponding rotation of said cam shaft which causes said cam housing to move axially toward said axle shaft; and wherein said cam assembly comprises a lever stop that ensures said lever has an angle of maximum rotation from said closed position that is less than 180o.