Hey guys, I’m new, nice to meet you all. anyways, about two years ago I bought what I was told to be a “classic” schwinn from the 70s or somethin. The thing is it had its original 70s tire on it and needless to say after a few months of use the tire blew out and now I am having THE WORST time finding a replacement tire, I’ve gone to every bike shop in my community and none of them can help me out, if one of you guys could please clue me in on what size of tire I would need I would greatly appreciate it. Thanks!
Maybe this?
http://www.unicycle.com/Shopping/shopexd.asp?id=290
Are there any markings on the tire/rim that could be used for identification?
Hey small change, welcome to the site.
John Foss is your man, he’ll be along shortly, can I get you a cup of coffee while we wait?
Did somebody call? If it’s a unicycle, you probably need this tire:
http://www.unicycle.com/shopping/shopexd.asp?id=676
Hmmm, they look suspiciously the same in the photos, but S-7 is the rim type on those old Schwinns. I don’t know about S-5. In any case it should say on the old tire which rim type it needs to fit. Both are outdated “oddball” sizes that, as you know, don’t fit today’s more standardized rims.
If you’re willing to dig around (on eBay and elsewhere) you might be able to find one of the original whitewalls, or black Schwinn “Unicycle” tires. For ride quality it won’t make much difference, but those old whitewalls sure looked cool. 
Welcome to the forums. Please post unicycling-related stuff in the rec.sport.unicycling forum, and always, always put your question in the thread title.