Growing up, Matt had an amazing tire swing in his yard. They put it up when he was about 7, and I remember swinging on it in our early dating years...you never get too old for a tire swing (perhaps just too heavy or too dizzy!) We decided it was time to bring that tradition to our yard.
Strangely, we found almost NO tire swings online that were meant for hanging on a tree (and let's face it- a tire swing hung 6 feet up on a playset is just not the same). After much searching, we found the WOSS-Gear-Tire-Swing-Hanger. They also make slack-lining gear, so we guessed that it would be very strong- and it seems to be.
I went to our local tire store and asked if they had any old tires, and they kindly gave me one for free. We scrubbed it down with dish soap and a strong hose, drilled a few holes for drainage in the bottom of the tire and sanded down the inner edges so that little legs wouldn't get scratched up. The tire is pretty small- fits our little ones fine right now. In the future it would be very easy to get a bigger tire and swap it out.
Installation was relatively simple- using a long ladder up against the tree branch, we looped a strap around a strong tree branch and fed it through a cam buckle. Using a carabiner clip, attach a 6 foot chain (adjustable) to the tree strap. Loop each of three straps through itself, around the tire. Hook these three straps to a carabiner on the bottom end of the chain and swing! The straps are rated for up to 500 lbs. I don't think our tree branch is rated quite that high, however, Matt did bounce around on it for a bit, so we feel confident that it is strong enough for our needs. Obviously, be very careful installing and using the swing.
Of course, when you have a new tire swing, the best thing to do is to invite some neighbors and friends over to share it!