Have a 50s Deki Bicycle 26" I need a rear tire that fits a Araya rim 26x1 3/8 b/e Where can I buy one?

Have a 50s Deki bike 26" I need a rear tire that fits a Araya rim 26x 1 3/8 b/e Where can I buy one?

First things first: Where are you? It'll be helpful to know that so we can point you to a shop in your part of the world.

As for the tires... There are a whole bunch of different 26" tire standards, many of which aren't interchangeable. There are even two different, incompatible, 26" x 1 3/8" standards. One of them has a bead seat diameter of 590 mm and the other is 597 mm. Sheldon Brown has a page specifically about 26" tires on his web site:

https://www.sheldonbrown.com/26.html

If your current tires list a size in ISO/ETRTO notation, it'll help you identify which you have (without the need to measure). Look for a number like 35-590 or 35-597. The part before the hyphen is the width of the tire. The part after the hyphen is the bead seat diameter, which will positively identify which 1 3/8" standard you need.

The most common 26" tires fit mountain bikes made in the past 20+ years, and those have a BSD of 559 mm. They won't even come close to fitting rims meant for either 26" x 1 3/8" standard. You can identify these because their tire widths will generally be expressed as a decimal number instead of a fraction. For example, 26" x 1.75" instead of 26" x 1 3/4".

Is there a phone # that I can call you to tell you about this tire? I live in Pa.

Best thing to do is bring it into your local bike shop (LBS) and have them take a look at it. Generally you want to stick with the exact same tire (in terms of tread pattern and of course ISO diameter) Sometimes a 26" tire can have the same ISO diameter but will be a different tread which means it won't actually fit which I learned the hard way after blowing off a customers new tire several years ago. ISO 559 is ok in my book as is 650b but beyond that 26" can burn to death!! Such a pain in the butt to deal with.

Some shops do have those sizes in stock and some don't but generally most if not all can order them and install them for you. If you do it yourself it is helpful to know that while the tire might be able to hold a higher pressure your rim might not so be careful and best thing to do is use a hand pump and do it slowly checking that the bead is seated all the way around and probably not going above 50psi.