Originally Posted by
Racing Dan
I dont know for sure. I cant find the current ETRTO or ISO standard chart. I do agree its weird having the same max pressure for every imaginable combination, and I bet its not the case either. I just cant prove it right now.
I think the ETRTO standard max pressure on hookless rims is 73 psi for tyres up to 28 mm and 65 psi for 30 mm and above. But the various tyre manufacturers don’t necessarily comply with the ETRTO standard. For example Conti state a max 73 psi for all widths of their GP5000S TR. They say that they test their tyres at 110% of this max pressure on the widest rim allowed in the ETRTO rim/tyre width chart. Other tyre manufacturers use slightly different methods, so there is no real standard here.