31. Having the “Snaps Toogle” activated, create a Tube in the middle of the tire. Then adjust the dimension as me. Push them until you reach the limit of the tire. Be sure that the tube is just a little bit bigger. You can add more sides if you want to make it rounder:
32. Select the polygons from the interior and detele them :
33. Now select the same edges as me and chamfer them using the same amount, or until you reach the limit of the high poly model.
34. If you will hide the edges, you will see that the polygons are visible and its not looking very good. To solve this, select all polygons, then go to the “Smoothing Groups” tab and select a smoothing group. This will smooth the look of our object without adding polygons :
35. Create a back-up of this file. Now select the high poly model then go to Export > Export Selected and save the model as OBJ :