Abstract: A foldable bicycle frame comprising a steering part comprising a first bar provided with at least one ring at a first end of the bar and a handlebar stem pivotally connected to the first bar at a second end for coupling to a front wheel; a seat support part comprising a second bar provided with at least one ring at a first end of the bar and a adapted to be coupled to a seat at a second end; a rear paddling part comprising a third bar provided with at least one ring at a first end of the bar and a adapted to be coupled to rear wheel; a tubular cylinder connecting unit about which the rings of the first, second and third bars are pivotally mounted, wherein the rings may be aligned and fixed in at least one alignment.