benjamin163

It seems very complicated all the figures on an inner tube box.
to my mind i just need to know my wheel circumstances (28 inch) and my tyre width (33 mm).
but the front of this box has 3 sets of figures eg 18-622 followed by 28x0.75 followed by 700x18c. Can anyone tell me what each of the figures on the front of this box mean?

BTinNYC

The inner tube fits a range of similar tire sizes.
The three numbers in a line represent the same tire size stated using different standards.

benjamin163

Thanks for the reply.
I can see the second and third figures are inches and millimetres but the conversions are quite rough aren't they?
And I still can't work out the first figures and why they are in bold. Any idea?
Also, there is a 'c' after the small '700' above the big '28"'. Now I'm presuming this is the circumference of the wheel in mm and inches. So I'm guessing the 'c' there denotes circumference. But what does it stand for after the figures at the end eg '700x18c' or '700x28c'? That can't be circumference. I'm sure those figures denote the width of the tyre. So what's the 'c' standing for?
Any help gratefully received.

dedhed

Look for ISO sizing on your tire. i.e. 23-622.

​​​​​​https://www.sheldonbrown.com/tire-sizing.html

Crankycrank

+1. And I find the ISO is the most precise sizing. When looking at Sheldon's site notice how many different 26" tires there are but each has a different ISO size and they are often not interchangeable although tubes have a much greater fudge room if you can't find the exact same size.

DiabloScott

That is a lot of data to put on an innertube box.
I think Schwalbe is purposefully being confusing so that shoppers have to come here to ask WTF? and then they see ads for more Schwalbe products.

Lombard

As you can see from this site, bike tire sizes can be even more complicated than car tire sizes.

The ISO size is the actual size. Any others are what they are called in marketingland. So a 700c tire is made to fit on a 622mm rim which is actually 24.5 inches. 700mm is actually 27.5 inches. But wait, how can a 700c x 23 tire be the same diameter as a 700c x 32 tire? Answer: It isn't, but it's called that anyway. 700 is a nice round number people can remember.

Are you totally confused yet? Bottom line, your tube will fit any 700c tire that is between 18mm and 28mm.

Iride01 

The C after the tire width can mean different things depending on what tire manufacturer you ask. Schwalbe is one that says that it simply is a throw back reference to the days of French tire sizing. Continental says that when seen on a tire, it means that tire should only be used on a rim with a hook or crochet bead seat.

You have a tube. Your only real concern is the width and diameter of the tire it is made to fit in. Not so much what type rim. Although you might want to pay attention to the stem length if you don't have profiled rims. 60mm will leave a lot of valve stem sticking up out of the rim. But it sometimes is harder nowadays to find shorter.

grumpus

The first column at the bottom is the ISO (previously ETRTO) actual dimensions in millimetres, so tyre widths from 18 to 23 mm and rim diameter* of 622 mm
The second column is the customary German and Scandinavian 28 inch sizes, which are the equivalents of the sizes in the first column
The third column is the French (and global) 700C which is also 622 mm (based on the 700 mm overall diameter of a historical tyre/tube standard. Note that there is also an obsolete 700A size, and 700B which is 635 mm and more commonly known as 28x1-1/2 English, and NOT the same as "28 inch" mountain bike tyres which is actually just marketing speak for wider 700C tyres).
The remaining columns are some wider 700C tyres, with the German and French sizes alongside, then a couple of 630 mm sizes which are more commonly known as 27 inch, as used on many older British and American sport and touring bikes. Note that although 700C and 27 inch tubes are interchangeable with the correct width, 700C and 27 inch tyres are not interchangeable, and 27 inch rims are actually larger than 28 inch rims (unless they're 700B**).

* Actual rim diameter is measured where the tyre bead sits on the rim, i.e. the tyre inside diameter rather than the overall rim diameter. Rims may be marked with their version of ISO for example 622x19 which would suit e.g. a 35-622 700X35C tyre.
** If you think that's fun ask about 26 inch tyres.

Bill Kapaun

match up the 622-xx number with the tire.
I prefer to get a tube whereas the tire size fits fits in the middle of the range of the tube.
Example- Your tube is (622-)18 to 28mm
I'd find that tube ideal for a 23mm tire. (18+28)/2=23. (And quite good for a 20 or 25mm.)
I like my tube to stretch SLIGHTLY when filling. Enough to remove any folds/creases, but not over stretching which will thin the tube and require slightly more frequent "topping off" the air.

benjamin163

So many great answers here,
Yes I always know which inner tube to get but I always wondered why the descriptions were so damn complicated.
Now I know, thank you.

alcjphil

Schwalbe always provides complete information about inner tube compatibility on the packaging of their products. It is what they do. I worked for a company that distributed Schwalbe products. The ISO measurements are always the most reliable, but inner tubes have a huge fudge factor. As an aside, most tire measurements that are in inches have nothing to do with the actual size of the wheel rim. Rather, they relate to the outside diameter of the inflated tire. So, the 28" nominal tire size on the inner tube box is only for narrow road tires, but the same rim size is also designated as 29" with wider mountain bike tires. Sounds confusing except that it isn't a big deal. For someone using 700 x 32 tires, an inner tube that claims to work for 700 x 28 tires will probably be just fine, the inner tube is just a baloon that will fill up the inside of your tire and cause no problems