I have a girls 26 inch Columbia touring bicycle, its old. It needs new tires, on the tires is the size of 26 x 1 3/8 inch. Yet, all tires at Walmart are too small to fit the rim. I even went to a 27 inch and it was way too big. My question is (and I have searched extensively and found no answers) Will a Schwinn tire fit this bike? Or, will those 700mm fit. Thanks
The tire brand alone won't help. Over the years bike makers and tire makers have invented an amazing range of sizes. It keeps us on our toes…
I'd guess that the tires you found at Walmart were 26 x 1.375 (or some other decimal size). You'd think that 1.375 and 1 3/8 inches would be the same. Alas, they are not. This question, Why does a decimal sized 26“ tire fit my rims but a fractional sized 26” tire doesn't?, explains in more detail.
What you need to do is to find a tire with a fractional size (or look for a tire marked 35-590 or 37-590 – this is an ETRTO/ISO tire size, the numbers are the width (35 mm or 37 mm) and the "bead seat diameter" of the rim (590 mm). Most tires will be marked with this number and it will let you be sure you're getting the right size.
Your local bike shop will probably be able to get these for you, or if you'd rather order online one place that carries a good selection is Harris Cyclery. The link will take you to their selection of tires.