Bicycle Mechanics - How can I tell which size the wheels on my bike are?

from where to where should I measure the wheel ? or is it printed on the wheel somewhere ?

it's a "winner" mountain bike if that's of any relevance

there is a very good chance it's 26 inch, or 559mm iso.

Look at the side walls of the tire, it should say.

yes it does say 26 x 559 on the tire but the thing is it's not the original tire on it.
I was hoping there is a print somewhere on the rim as well.

it gets more confusing because I read somewhere you need to measure it from rim to rim, and that came out 22".
how can that be ? am I measuring it wrong ?

yes it does say 26 x 559 on the tire but the thing is it's not the original tire on it.
I was hoping there is a print somewhere on the rim as well.

it gets more confusing because I read somewhere you need to measure it from rim to rim, and that came out 22".
how can that be ? am I measuring it wrong ?

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

If the tire fits the rim it doesn't matter if it's the original or not and the sidewall size marking of the tire is still correct. Your wheel is the very common 26" MTB size (ISO 559).

BTW, the 26" number is an approximation to the overall outside diameter of the rim and tire together, not just the rim, and 559 mm = 22.0 inches.

it gets more confusing because I read somewhere you need to measure it from rim to rim, and that came out 22".
how can that be ? am I measuring it wrong ?

Whoever told you to measure from rim to rim was thinking of car wheels, not bicycles. If they thought it applied to bicycles, they don't know bicycles.

Mountain bike wheels are pretty much all the same size. The tires are usually about 2" in diameter so the whole wheel is approximately 26" and is referred to as a 26" wheel. Even if you put a tire that's only 1 1/2" in diameter on it, and the wheel is now 25", we still call it a 26" wheel. If you want to buy a new tire, get one that says 26" on it. The only thing you have to worry about is how wide the tire is.

It gets more confusing because I read somewhere you need to measure it from rim to rim, and that came out 22".
how can that be ? am I measuring it wrong ?

That's right, 22" = 559 mm. "26 inch" is supposed to refer to how big the tire is outside-outside. It doesn't, though, because there tires of different heights that fit on the same rim and they all get called "26". Just go the ETRTO rim size (559) and it'll be less confusing.

If you want to buy a new tire, get one that says 26" on it. The only thing you have to worry about is how wide the tire is.

Not exactly... you need to get one that says 26 X 2.00 (or 26 X any decimal number). If a tire says 26 X 1-3/8 (or 26 X any fractional number) it will not fit on a modern mountain bike - those are different sizes. See the Sheldon Brown page for clarification.

Not exactly... you need to get one that says 26 X 2.00 (or 26 X any decimal number). If a tire says 26 X 1-3/8 (or 26 X any fractional number) it will not fit on a modern mountain bike - those are different sizes. See the Sheldon Brown page for clarification.

+1 You need decimal tires, not fractional. Fractional tires are not the same size.

Those vintage fractional sizes really throw you for a loop, especially if you get a bike where the tires are so rotted you can't read the size. It's trial and error time at the LBS, if they let you.
You'd think that somebody would just throw out the whole "older" ISO system and replace it with a decimal system that EVERYBODY could understand. Convert every tire size to a two number system that would eliminate the confusion. Sort of like 700x40c - but actually meaningful. Like "tire diameter at rim" and "tire width at rim".
Since China basically owns the lions share of bike manufacturing, I'd expect them to do it.
Sheldons info is really helpful.

24" is not the same as 24", which is not the same as 24".

Get it?

24" is not the same as 24", which is not the same as 24".

Get it?

Twenty inches is not always equal to twenty inches.

You'd think that somebody would just throw out the whole "older" ISO system and replace it with a decimal system that EVERYBODY could understand. Convert every tire size to a two number system that would eliminate the confusion. Sort of like 700x40c - but actually meaningful. Like "tire diameter at rim" and "tire width at rim".
That's exactly what the ETRTO/ISO system did. It replaced a bunch of similar, confusing, obsolete and misleading sizes with two specific number sets; rim diameter and tire diameter and width. If the ETRTO/ISO size of your tire matches the ETRTO/ISO size of your rim, they fit. If not, they don't. How much simpler could it be?

There are tires either too wide or two narrow to be a good fit on their otherwise matching diameter rim but any other sizing system won't address that any better than the ETRTO/ISO system does now. At some point you have to realize what you need or get some knowledgeable assistance.