First of all it is necessary for us to make one segment of a tire cover. We shall do it of a plane:
After that, on the top view, it is necessary for us to move a few vertexes at a plane that such detail has turned out here:
We pass to the front view and we move vertexes:
Now we select that that at us should come out:
and we do extrude faces (Edit Polygon / Extrude Face) two times (do not forget to put before this a tick in the menu Polygon / Tools Options / Keep Faces Together, if it at you is necessary)
Further it is necessary to remove some faces which to us are not necessary
At the given stage if you wish to receive realistic model, it is necessary to edit considerably the obtained segment, to add facets, etc. If at you while not enough experience that it is possible to leave so. Because the main thing in this lesson to understand a principle
Now to us it is necessary to move a pivot point in as it is shown below
