Bicycle Mechanics - Tires sizes English vs metric

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : Tires sizes English vs metric


vulpes
06-23-07, 07:03 AM
I found 2 brand new 26" tires for $5 at a thrift shop yesterday. Couldn't pass em up. They are 26 X 1 3/8. I've read Sheldon's article stating that english and metric are NOT interchangable. But will they still fit on a 26" rim that currently has a metric sized tire on it?


well biked
06-23-07, 07:13 AM
I found 2 brand new 26" tires for $5 at a thrift shop yesterday. Couldn't pass em up. They are 26 X 1 3/8. I've read Sheldon's article stating that english and metric are NOT interchangable. But will they still fit on a 26" rim that currently has a metric sized tire on it?

You need to look closely on the tires and find the ISO number (this is the bead seat diameter) for your tires. There's no interchangeability, they're made for a specific size rim in terms of bead seat diameter. And to make matters more confusing, there are at least two DIFFERENT 26" x 1 3/8" tire sizes (different ISO). Here's Sheldon's chart on tire sizing:

http://sheldonbrown.com/tire-sizing.html

tcs
06-23-07, 07:14 AM
There are a number of "26 inch" tires sizes. ISO559 (mountain bike), ISO571 (narrow, time trial; wide, old Schwinn middleweight), ISO584 (obscure French size), ISO587 (really, really obscure Japanese size), ISO590 (English racer/3-speed: this is the size you bought at the thrift shop), and ISO597 (obscure British/Schwinn size). None of these tire sizes are interchangeable. Your ISO590 tire, also called 26x1 3/8, also called 650A, will only fit on a rim designed for that size.

HTH,
TCS


well biked
06-23-07, 07:19 AM
There are a number of "26 inch" tires sizes. ISO559 (mountain bike), ISO571 (narrow, time trial; wide, old Schwinn middleweight), ISO584 (obscure French size), ISO587 (really, really obscure Japanese size), ISO590 (English racer/3-speed: this is the size you bought at the thrift shop), and ISO597 (obscure British/Schwinn size). None of these tire sizes are interchangeable. Your ISO590 tire, also called 26x1 3/8, also called 650A, will only fit on a rim designed for that size.

HTH,
TCS

I agree it's likely the OP bought ISO 590 tires, but I've got ISO 597 tires (Schwinn S-6) that also say 26 x 1 3/8 on them. They're not really "obscure," there were millions of Schwinns made with them, and they're still available. That's why the OP can pretty much ignore the 26 x 1 3/8 markings and just look for the ISO size on the tire-

vulpes
06-23-07, 07:21 AM
There are a number of "26 inch" tires sizes. ISO559 (mountain bike), ISO571 (narrow, time trial; wide, old Schwinn middleweight), ISO584 (obscure French size), ISO587 (really, really obscure Japanese size), ISO590 (English racer/3-speed: this is the size you bought at the thrift shop), and ISO597 (obscure British/Schwinn size). None of these tire sizes are interchangeable. Your ISO590 tire, also called 26x1 3/8, also called 650A, will only fit on a rim designed for that size.

HTH,
TCS

Yep they're 590's. How'd you guess? I guess they will go in the yard sale. Maybe I can get $10 for them and double my investment. :p

DMF
06-23-07, 08:15 AM
Yeah. Sell them as special rare tires on eBay or craigslist.

roccobike
06-23-07, 08:16 AM
Yep they're 590's. How'd you guess? I guess they will go in the yard sale. Maybe I can get $10 for them and double my investment. :p
If they're in good shape and they're gumwall and the brand name is "Raleigh", PM me! Kenda's I can get all day every day but not Raleighs.

Sheldon Brown
06-23-07, 11:04 AM
I found 2 brand new 26" tires for $5 at a thrift shop yesterday. Couldn't pass em up. They are 26 X 1 3/8. I've read Sheldon's article stating that english and metric are NOT interchangable.That's not correct, and I don't believe I ever said that. Almost all tires are marked in BOTH "English" and metric systems.

What I did say, which you may have misread, is that, for the inch based systems, DECIMAL and FRACTIONAL sizes are never interchangeable, even for the same nominal diameter.


But will they still fit on a 26" rim that currently has a metric sized tire on it?

Depends on the metric size you're speaking of. Your tires are 590 mm in metric (or maybe 597 mm.)

Most common "26 inch" wheels on newer bikes are the DECIMAL 26" size, or 559 mm in metric.

See also: http://sheldonbrown.com/26

and: http://sheldonbrown.com/tire-sizing

Sheldon "Misquoted" Brown