I bought new tires for my girlfriend. She bought an original 1960's schwinn. And I bought 26.75 tires for them and i cannot get them on. I've been cycling for a long time like since I was 14 and I've changed a million times but I cannot get the tire on for the life of me. The tires that were on it say 26 3/4 and the tires look to be the same size but idk ar am I just stupid or something.
by RaveGang
5 Comments
tire seems to be the right size, try to make sure your tube is only slightly inflated and use tire levers if you have them
26 1 ¾ is 571mm internal bead diameter
26″. Are 559mm internal bead diameter
These are not interchangeable. Decimal and fractional measurments are not compatable
Sorry to say, those won’t fit. The measurement has a fraction in it which is a different rim diameter than the tire with a decimal in it. In ISO measurements the first number is tire width and the second is the rim diameter. The fractional tire is a 47-571 and the decimal tire is a 47-559.
Those are different tire sizes. 26″ x 1¾” (Schwinn S-7) has an ISO diameter of 571mm. Modern 26″ tires have an ISO diameter of 559mm. One will not fit on the other. The vintage Schwinn sizes are often very obscure.
See Sheldon Brown’s article on tire sizes for more info: https://www.sheldonbrown.com/tire-sizing.html
You need the 26-1¾ tire size or you need modern 26″/559mm wheels. I’m not even sure how easy those are to find. I only ever see 26-1⅜, which are Schwinn S6 if I recall.
There were *several* different “26inch” wheels between Schwinn, Murray, Huffy, Hiawatha, and other bike companies.