Originally Posted by 2manybikes
You bought the wrong tire. The ones that say 1-3/8 shown as a fraction are different from the ones that show it as a decimal like 1.75 or 1.95 etc. two different wheel sizes. The 1-3/8 are older, there may not be studded tires for that size. None of the decimal size tires will work for you.
It gets worse, there are many 26" sizes. Is it an old Schwinn? It may be different still.
Do go see Sheldon Browns page on this to understand. It will give you enough information to identify the old tire size. They are marked.
Specifically:
http://sheldonbrown.com/26
Sheldon "ISO/E.T.R.T.O." Brown
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