Abstract: A skateboard that can be converted between a scooter and a skateboard has a bracket that is pivotably mounted on the footboard and can be pivoted between a first scooter position and a second skateboard position. The bracket is longer than the footboard by an amount, so that, in the skateboard position, the bracket forms a clearance between itself and the end of the footboard that is sufficiently large as to enable the skateboard to be gripped through said clearance and carried.

Abstract: The roller board having a footboard and two front wheels mounted on a front axle can be steered in that the front axle is connected to the footboard pivotable about an axis perpendicular to the plane of travel. The front axle is resiliently coupled to the footboard in the direction of rotation.

Abstract: A convertible two-wheeler which can be converted from a balance bike to a bicycle without tools by hooking and locking a crank assembly into two receptacles of the frame. The crank assembly has a fastening element that can be connected in a form-fitting manner to the two receptacles on the frame, the fastening element consisting of two elements which are interconnected by means of a pivot bearing and between which the bottom bracket is clamped, the two elements being braced against one another by means of an eccentric lever and the length of the eccentric lever being adjustable.

Abstract: A harness for boardsailing has straps 42, 48 which are swivably mounted on substantially rigid panels 36, 38 by couplings 39, 47, 50. The couplings 39, 47, 50 each comprise two parts which snap fit together through an aperture in the panels 36, 38 and swivel in the apertures.