hey @JBadalian , i was just thinking about this again during my last workout and came up with an inaccurate but probably good enough way to measure this! again, this is with the new zipp 404 hookless wheels that have a 23mm internal width and 28mm pirelli p zero race tubeless tires. I got two pens out, pressed them against the tire and tried to make them as straight as possible and measured the distance between them, so not a very accurate way to measure but i dont’ have calipers!
anyway it was 30mm measured that way at 60 psi, which is what i’ll ride them on. i’m guessing the wider 25mm internal width of the 303s’ would give them an extra mm or two! Hopefully that helps