The reason I ask is the bloke in the garage has put them both at 38 and whilst I was expecting them to feel a little odd at first they really do feel alittle unnerving on the tight bends. However only got 25 smiles on them and the ride to work this morning was wet and slippery.
IIRC it's x 14.7 YMMV though being further west than I am.
BTW don't try and get the conversion wrong eg military aircraft main wheel needs 250 psi, brave person puts in 250 bar . Dunlop the wheel manufacturer was amazed it didn't blow up as they expected it to only survive a 10 x overpressurisation.