On Sun, 11 Nov 2018 10:29:03 -0800 (PST), Andrew Chaplin
wrote:

Has anyone a pointer to a table of pressures for such a tire? Barring that,
a formula for their calculation. The tires have to carry a load of
about 100 Kg.

I've got a smartphone app from Berto Tire (downloaded from Android
Play Store) that says for a normal road bike with 650B x 47 tires, 22
lb bike weight and 220 lbs rider, the tire pressure should be 45
psi(rear) and 32 psi (front).

cheers,

John B.