Yes, the measurement system is the same everywhere and you need the wheel size somewhere in there, but the size of the tire (if you were to take a slice of its profile) is in metric.
No, like I said, tires are sized in both. The width of the bead is given in millimeters, the diameter of the bead is given in inches, and the height of the sidewall is given as a percentage of the width aka Aspect Ratio.
Cut it and you’re left with a U shaped slice measured in mm (even if it’s a ratio that’s used for both legs, if you apply a ratio to a measure in mm, the result is something you measure in mm). The tire itself is measured in mm and then the last number is the size of the wheel it’s wrapped around.
That’s the point of view I’m thinking about, the red part is the tire and you only need the first two (metric) numbers to know what it looks like, the wheel size doesn’t influence the width or sidewall height of the rubber.
Also, past a certain point you’re back to imperial measures (35/13.5 x 20 > height x width x wheel) or you might not even have the height/sidewall at all (14.9-42 is 14.9 width for 42" wheels but that’s mostly for tractors.
At least in the United States, tire sizes are a goofy mixture of the two, plus an indirect measurement.
A 205/75R15 tire is 205mm wide bead to bead, fits a 15 inch diameter rim, and is 153.75mm from bead to tread (75% of its width).
Yes, the measurement system is the same everywhere and you need the wheel size somewhere in there, but the size of the tire (if you were to take a slice of its profile) is in metric.
No, like I said, tires are sized in both. The width of the bead is given in millimeters, the diameter of the bead is given in inches, and the height of the sidewall is given as a percentage of the width aka Aspect Ratio.
Cut it and you’re left with a U shaped slice measured in mm (even if it’s a ratio that’s used for both legs, if you apply a ratio to a measure in mm, the result is something you measure in mm). The tire itself is measured in mm and then the last number is the size of the wheel it’s wrapped around.
That’s the point of view I’m thinking about, the red part is the tire and you only need the first two (metric) numbers to know what it looks like, the wheel size doesn’t influence the width or sidewall height of the rubber.
Also, past a certain point you’re back to imperial measures (35/13.5 x 20 > height x width x wheel) or you might not even have the height/sidewall at all (14.9-42 is 14.9 width for 42" wheels but that’s mostly for tractors.
Cut it and the auto shop is going to make you pay for the merchandise you just destroyed.
The diameter of the bead, which is measured in inches, is a critical feature of the goddamn tire.
You really chose the right name.
Goodnight.