Hello, I have an early, Girls 1960's JC Higgins Flight liner that needs tires. Could someone please tell me the tire size and ISO number I need for this bike? Thank you

If the bike has old tires still on it, you should be able to find the markings on them to verify what size it has - provided they're still legible. That would tell you definitively what size will work.

If not, this link indicates it was likely the older 26" x 1.75" tire. It's an older US bike, so that makes perfect sense.

https://ratrodbikes.com/forum/thread...-advice.43074/

Per the late Sheldon Brown's tire size cribsheet, that should correspond to an ISO 559.

https://www.sheldonbrown.com/cribsheet-tires.html

But it might be worth taking one of the old tires with you for comparison when you go to buy if you're buying locally. Or if you don't have the old tires, it might be worth taking one of the old wheels to your LBS and asking them for their take on tire size. So-called 26" tires come in a rather large number of ISO rim sizes.

Thank you