Warning: The making of this project is dangerous - people have been injured just attempting to create this swing - let alone riding it. If you try it - be sure to have some help, as it requires some serious brute force. Now, without further ado, here's how to make a Horse Tire Swing.
Begin by finding a bias-ply tire. Do NOT use a steel-belted tire or the children who using this swing will be injured. Cut out this pattern on the both sides of the tire, and make bolt-holes where the dark circles are drawn on the diagram. Take your time and be sure that both sides of the tire pattern are the same.
Now comes the brute force part of the equation. Unfold the tire as shown and turn it inside-out. This is much easier said than done - a friend's help will prove invaluable. Try to flex the joints open - this may required you to heat the rubber slightly to soften it.
The rubber will want to go back to its original form, so placing the first bolt is a critical step. Have a friend hold the tire open while you place the bolts. Begin with the nose - which will prove to be the easiest bolt as it is nowhere near any creases. Simply thread one of the four inch bolts through both sides of the horse's nose and tighten the nut into place.
The next 4" bolt will attach the jaw to the neck and will actually be going through four layers of tire - two in the jaw and two in the neck. Again having a friend hold the tire, thread the bolt through all four holes and tighten the nut on the far side. Now the 4" bolt on the lower neck will be much easier to place.
Fold the tail backwards over itself and place the 2" bolt through from the front - with the nut on the back side of the swing.
Place the 6" bolt through the saddle of the horse and tighten the nut enough that it doesn't stick out. If so, use a hacksaw or grinder to cut off any excess length of bolt which might scratch a child's legs. Be sure to use a plastic bolt cap here as well.
Now place the old fan belt around the horses neck as a reigns for the child to hold onto while swinging.
Thread the front hanging rope or chain through the cut on the top of the horse head and be sure to go around the bolt holding the jaw to the neck as an anchor. Thread the rear hanging rope or chain through the loop in the tail.