Inner tube sizes and what's written on the box
 

So I have a tyre that is 44-622 - 28x1.65 - 700x42C. Unfortunately it has gone flat so I'm looking at schwalbe inner tube boxes so I can replace that flat but I need to be sure of something. On the box it says:
40-622 - 28x1.50
42-622 - 28x1.60
47-622 - 28x1.75

But it doesn't say my exact size of 44-622 or 28x1.65 on the box. Logically it should fit my tyre fine by what I remember. Am I to understand correctly that it should fit my tyre fine? I haven't changed a tyre in a year cause I haven't had a flat since and now I have forgotten a little how to read bicycle tyre :foo:. Thanks :thumb:

That tube will be fine. Most tubes are designed to fit a range of widths. As long as yours is within the range listed it will work. The 44-622 is the inflated width in mm (44mm) & the diameter of the bead seat of the tire (622mm-also known as 700c, 28" & 29" using different standards) Here's a good article to explain the different sizing standards which are confusing as h*ll if you're not aware. Tire Sizing Systems (sheldonbrown.com) The ISO standard is the most precise as the "inch" system has at least 5 different non-compatible sizes for a "26 inch" tire.

40-622 - 28x1.50
42-622 - 28x1.60
47-622 - 28x1.75

All of the above sizes will work with your tire = 44-622 - 28x1.65 - 700x42C

I'll add that labeled sizes are not always the same actual tube dimensions. Today at the local non profit our flat fixer (and general inventory hound) showed us a tube with an inked label of 26x1.5/1.75 and a molded on size of 26x2. Andy

Inner tubes are very forgiving since they are baloons.

Half the tires I remove from rims I service always have the incorrect tubes.

People just seem to use whatever they have or whatever they can find.

Helps me sell more inner tubes.

Ideally you want the tube to not be so big that it wrinkles or kinks inside the tire/rim. The wrinkles and kinks sometimes can be felt as regular bumps every rotation of the tire and they are points that might be more prone to developing a leak.

Nor do you want it to be so small that it stretches a lot to fill the cavity created by the tire/rim. The more a tube stretches, the more likely it's going to give you quick flats instead of slow flats when something punctures it.

That said there is no standard I know of that says how the mfr's must label their tubes or what dimensions of the tubes must be for what tire. So even if you get a tube that is expressly for a particular size tire. A tube from another manufacturer for that particular size tire might be different.