I'm replacing the inner tube of old bicycle with tire code: 47-559 (26 x 1.75). I bought a new tube that has spec: 26*1.75 - 2.125 (47/57- 559).
However, the diameter of the new inner tube is too large, such that it can't fit (folded inside the tire). It is also obvious that the new inner tube has larger (in diameter) than the rim.
I thought that using the same ISO code (47-559), I would get the correct diameter, but it isn't.
Then I realized, there's a code 26 x 1.50 on the old inner tube.
Can anyone help me with this matter? Is this mean that I can't use the ISO code (47-559) for finding a replacement?