Today I had my first encounter with the wildly variegated world of inner tubes / tires / wheels sizes. My wheel shows this, no info readable on the tire:
I already discovered that 28x1.5 and 28x1 1/2 are two completely different sizes, as I bought the former inner tube and I couldn't manage to fit it in (it was too large). Now my question is:
I found a shop that sell 40-635 (28x1 1/2) inner tubes. Are they the same as this 22x635 (28x1 1/2)? Can I buy it safely or the tire itself may play a role?
If they are, why does the first number change so much? I thought it was the width expressed in millimeters!