Let me provide some final notes. I used components that were rated at a weight capacity greater than anything that'd be on the swing. The s-hooks were rated at over 600 pounds, the Clip Hook was over 500 pounds, the Connector Links were over 500 pounds, and the Swivel was over 400 pounds. This means that ANY adult who can fit between the chains, or can stand on the tire, will be safely held by the hardware used. If you want, you can certainly use lighter-duty components, which will naturally cost less money. But, I wanted to test the tire swing, and I'm 200 pounds, so I wanted to make SURE that it was safe! So, I went with double weight protection just to be certain. The whole thing, except for the tire, cost about $60.00. You could buy the kit from one of the playset manufacturers. The kit runs just a hair under $100.00. Doing it this way gave me the flexibility to do what I wanted and hang it how I wanted, and saved money along the way. If anyone has any comments, I'm interested in hearing them. But, don't ask me to do an instructable on how to build the completed playset! I'm planning on building two elevated forts with a swingset between them & a walkway above them, tho the vertical supports for the forts are being planned to use telephone poles! And, if anyone does use this to build their own tire swing, I'd really like to know.
Also, the weight rating on the components you selected assumes a static weight. A 200 pound person swinging probably produces a lot more tension at the bottom of the swing arc than a 200 pound person just sitting on the swing. That said, in addition to the safety factor that you used, there is probably also a safety factor built into the numbers printed on the packaging.