Originally Posted by
Jipe
If you look at rim and wheel specifications given by the rim and wheel manufacturers, they also give a range of tires width that fit on their rim and wheels with a minimum and a maximum allowed width.
So its not only the ETRTO ISO specification that gives width limitations in function of inner rim width, the manufacturers also do it and they know the products they have designed.better than any user.
These charts are probably general guidelines. We do not know the reasons why you should not use a less wide rims. Your explanations are just guesses given as the explanation.
Another thing about the chart is that it does not consider the rim diameter. Were there tests done with all diameters? Are there separate charts for all diameters.