ISO 5775 Tire section width

[Rabbitbunny]

From what I can gleam from google this seems to be measured mounted, but on what width rim?

 

[alfeng]

From what I can gleam from google this seems to be measured mounted, but on what width rim?

Is that tire for a Schwinn rim? If so, there was probably only one rim width.

Like most rims from before 1980 (?), the rim's width is probably about 1" wide (outside-to-outside).

If you've got the inclination, you may want to relace the hubs with some contemporary 559-17 or 559-20 rims so you can use ANY standard 26" tire.

 

[Rabbitbunny]

For any tire on any rim.

It's a current standard.

http://en.wikipedia.org/wiki/ISO_5775

 

[alfeng]

For any tire on any rim.

It's a current standard.

ISO 5775 - Wikipedia, the free encyclopedia

The information in the Wikipedia entry is actually pretty clear ... at least, once you understand how it is presented.

You can mount a wider tire on a narrower than recommended rim ... you cannot mount a narrow tire on a wide rim ... THIS IS INDICATED IN THE FIRST TABLE.

I know someone who mounts 700-32 tires (Cyclocross) on 622-15 rims (MA40).

Presuming, for the moment, that you want to mount a 700c tire on a 700c rim -- you can theoretically mount a 'fat' 29er tire (622-52) on a 622-15 rim ...

Typically, it is recommended that a bigger tire is mounted on a wider rim BECAUSE a fat tire on a narrow rim will mean that mounting the wheel in the frame/fork will be difficult while the tire is inflated because if the brake caliper's pads are set for a narrow rim then they may be too close together to clear the inflated, "fat" tire.

What tire-and-rim combination did you want to use?

 

[ecarpet1]

Also when you mount a wide tire on a really narrow rim it will completely change the ride character of the tire. With mountain bike tires on really narrow rims the tire will have more lateral flex and the footprint will change. The angle of your brake shoes will be important to not touch the sidewalls also.

 

[Rabbitbunny]

This question has been answered by a wonderful man from Harris.

In short, the rim width is not included in the standard.

ISO 5775 Tire section width - Bike Forums

 

[Rabbitbunny]

Actually, I reverse that, The question was answered wrong by many people. Just in case someone is searching for this later, the correct answer is 'It depends on the section width'.

And here are those numbers;

Section Width -- Rim Width
16 -- 13
18 -- 13
20 -- 13
23 -- 15
25 -- 15
28 -- 17
32 -- 17
35 -- 17
37 -- 19
40 -- 19
44 -- 19
47 -- 19
50 -- 19
54 -- 19
57 -- 19
60 -- 21
62 -- 21

What this means is that a tire with a rated section width of 16 was measured on a 13mm rim.

 

[alienator]

Well you can throwout the idea that you can't put narrow tires on a rim that is wider than the width for which they were spec'd. Zipp and Hed are using significantly wider rims on some of their new wheels.

Why should ISO 5775 be any concern? People don't shop by that. It doesn't really help anything.

 

[alfeng]

Well you can throwout the idea that you can't put narrow tires on a rim that is wider than the width for which they were spec'd. Zipp and Hed are using significantly wider rims on some of their new wheels.

Okay, I'm an inquiring mind ...

What is the bead-to-bead measurement on those "significantly wider rims" & are they intended to be ROAD rims or are they actually intended to be used on a CX wheelset ... AND, regardless of the intended tire size, are they tubeless-capable?