New 26" inner tube different size to old 26" inner tube The new 26" MTB inner tube is much bigger than my 26" wheel (and old 26" MTB inner tube). I don't understand why. How to shopcorrectly for new tube?

The bike is 1990s Raleigh mountain bike.

Edit: the new tube is very loose both deflated and inflated. The new tube specs are 26 x 1.5 / 1.75 / 2.125 F/V according to the box and tyre

The old tube was 26 x 1.50 / 2.25 according to its box.
Check the label on the tube - does it say '26 x 1 3/8' by any chance? If so, this is actually a completely different size than the standard MTB 26". Get a tube that says something like 26x2.1 or 26x1.9 - the point is, the tire width should be expressed as a decimal, not a fraction. See Sheldon Brown's tire size chart.

Yeah, I know, it's stupid - I didn't come up with this system.