A green tire disposed on a toroidal support is introduced into a vulcanization mold. The spacer structure further includes: at least a first type spacer having a first height; and at least a second type spacer having a second height which is smaller than the first height. The webs delimit a recess, which surrounds the inner web and of which the depth measured parallel to the center axis of the cylinder-piston unit is at least a quarter of its width in a plane oriented normal thereto. The sleeve has a bellow section and protects the structural components of the bearing component from contamination. The valve means is in electrical communication with a sensor that detects the presence of a user and has a first fluid discharge port in fluid communication with the bowl portion and a second fluid discharge port.