Imho, those charts are rough guides at best. We run 25mm tires on the tandem with a team weight of 350lbs at 110-115 psi with no problems, which is way off what the chart would suggest.
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You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.