A compactable bicycle, comprising: a frame including a base frame portion having a rear wheel mounted thereto for engagement with a ground surface for supporting the compactable bicycle thereon and a steering structure rotatably mounted to the base frame portion and having a front wheel connected thereto for engagement with the ground surface for supporting the compactable bicycle thereon, wherein at least one of the base frame portion and the steering structure includes a first frame element having a first frame element locking surface, a first end, and a first aperture at the first end, and a second frame element having a second frame element locking surface, a second end and a second aperture at the second end, wherein the first and second frame elements (510, 514) are positionable in a first position in which the first and second apertures (520, 526) are generally aligned with one another and the first and second frame element locking surfaces (518, 524) generally face away from one another, and in a second position in which the first and second apertures (520, 526) are generally unaligned with one another; a plunger having a plunger axis, and having a first plunger locking surface, a second plunger locking surface, wherein the plunger is movable axially to a clamping position in which the plunger extends in both the first and second apertures (520, 526) such that the first plunger locking surface engages the first frame element locking surface and the second plunger locking surface engages the second frame element locking surface, characterised in that the plunger is movable axially to a release position in which the plunger retracts from the second aperture sufficiently to permit the first and second ends (518, 524) to be separated from one another, wherein the plunger includes a plunger body having a first plunger body portion and a second plunger body portion, wherein the second plunger body portion has the first plunger locking surface thereon, and further has at least one wedge member (750, 850) thereon that has the second plunger locking surface thereon, wherein a wedge member driver is provided on the first plunger body portion and is movable between a wedge member retraction position in which the wedge member driver permits the at least one wedge member (750, 850) to retract radially relative to the second plunger body portion and a wedge member projection position in which the wedge member driver drives the at least one wedge member (750, 850) to project radially outwards from the second plunger body portion to clamp against the second frame element locking surface. a frame including a base frame portion having a rear wheel mounted thereto for engagement with a ground surface for supporting the compactable bicycle thereon and a steering structure rotatably mounted to the base frame portion and having a front wheel connected thereto for engagement with the ground surface for supporting the compactable bicycle thereon, wherein at least one of the base frame portion and the steering structure includes a first frame element having a first frame element locking surface, a first end, and a first aperture at the first end, and a second frame element having a second frame element locking surface, a second end and a second aperture at the second end, wherein the first and second frame elements (510, 514) are positionable in a first position in which the first and second apertures (520, 526) are generally aligned with one another and the first and second frame element locking surfaces (518, 524) generally face away from one another, and in a second position in which the first and second apertures (520, 526) are generally unaligned with one another; a plunger having a plunger axis, and having a first plunger locking surface, a second plunger locking surface, wherein the plunger is movable axially to a clamping position in which the plunger extends in both the first and second apertures (520, 526) such that the first plunger locking surface engages the first frame element locking surface and the second plunger locking surface engages the second frame element locking surface, characterised in that the plunger is movable axially to a release position in which the plunger retracts from the second aperture sufficiently to permit the first and second ends (518, 524) to be separated from one another, wherein the plunger includes a plunger body having a first plunger body portion and a second plunger body portion, wherein the second plunger body portion has the first plunger locking surface thereon, and further has at least one wedge member (750, 850) thereon that has the second plunger locking surface thereon, wherein a wedge member driver is provided on the first plunger body portion and is movable between a wedge member retraction position in which the wedge member driver permits the at least one wedge member (750, 850) to retract radially relative to the second plunger body portion and a wedge member projection position in which the wedge member driver drives the at least one wedge member (750, 850) to project radially outwards from the second plunger body portion to clamp against the second frame element locking surface.