Quick-release skewer including a longitudinal rod with first and second clamping abutments at first and second ends of the rod, a lever pivotally mounted on the first end of the rod, the lever having a cam, a movable support member between the periphery of the cam and a first outer abutment surface, the movable support member including a locking surface capable of coming into contact with the cam and separated from the first outer abutment surface by a distance D1, the movable support member including an unlocking surface capable of coming into contact with the cam and separated from the first outer abutment surface by a distance D2 that is less than D1. The difference between D1 and D2 is between 2.0 and 4.0 mm. When the support member is in a locking position, the cam contacts the locking surface; in the unlocking position, the cam contacts the unlocking surface.