# Old American Tire size



## sam (May 6, 2019)

Just saw these . Their gray wheelchair tires but in the obsolete size 26X1.375
https://www.amazon.com/Sunlite-Whee...elchair&qid=1557176518&s=gateway&sr=8-2-fkmr0


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## PatrickZ (May 6, 2019)

I bet that's a mistake, and they are really 26 X 1 3/8 or 37-590s, which is the wheelchair standard.  I have seen similar tires on ebay advertised that way that turned out to be 590s.


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## FSH (May 6, 2019)

1 3/8 = 1.375


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## rideahiggins (May 7, 2019)

FSH said:


> 1 3/8 = 1.375



Not in tire sizes.


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## Eric Amlie (May 7, 2019)

They should be giving you the I.S.O size which specifies the bead seat diameter. That clears up any confusion.
From Sheldon Brown:

"Designating the width with a fraction instead of a decimal usually signifies a straight-sided rim, not a hook-edge rim. The rim/tire diameter is also slightly different. Let the tire buyer beware! There are similar problems with other Schwinn tire sizes. The most common difficulty is that the Schwinn 26 x 1 3/8 (I. S.O. 597 mm) interchanges with the British 26 x 1 1/4, not the British 26 x 1 3/8 (I. S.O. 590 mm)."


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## Roger Henning (May 7, 2019)

Nor does it interchange with prewar Schwinn 26 x 1.375 which are 599 bead seat tires.  Roger


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## dweenk (May 7, 2019)

Here is a link to Sheldon's tire size chart.
https://www.sheldonbrown.com/tire-sizing.html


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