Commuting - Weird Schwalbe Problem

The pair of Schwalbe Marathons in a 26x 1.38 that I ordered last week came today and when I took them out of the box they were huge--way too huge to fit on my rims. Definitely not 26s. Am I missing something here, or were they mismarked?

Looks like you got tires for 700c rims...

Ignore the box. What size is marked on the sidewall? That is what they are!

They say 26 x 1 3/8. But they are definitely not meant for a 26 inch rim--they're about 2 inches too big.

A 26 x 1 3/8 is a fractional inch sized tire for 590mm ETRTO rims for 3-speed road bikes. If you are trying to fit a 26 x 1.37 MTB wheel, then that explains your observation. You can't just convert a fractional size--which is nominal, not actual--to a decimal inch-based size. They are totally different.

And if that isn't confusing enough for you, there are actually two different 26 x 1 3/8 sizes, one is a 590 and the other is a 597 ETRTO.

Well that explains it. Thanks.

Schwalbetires.com is very good about putting the common size and the much clearer ISO size on all the tires sold. It is important to make sure you are getting the right size for your wheels, which starts with knowing what size wheels you have. 26" MTBs are 559mm rim diameter, 700c is 622, 27" is 630.
Schwalbe makes tires (especially the Marathon) for just about all rim sizes you might see. For the 26x1 3/8 you see they list it as a 37-590 not *-559 like a MTB tire.

Craig

Yes--I saw that tonight (grr) when I looked on the Scwalbe website...