Originally Posted by
moochems
Whoever packed them folded them wrong and kinked the bead. Tires weren't perfect round, but close enough that I have them a try. On my 27 inch araya rims the tires would not stay on the rim, even at 80% of Mac inflate. Between a slight out of round, and two blowouts (thankfully while garages) I returned the tires.
Modern 27" tires often have higher max pressure ratings than they did back in the day. If you're running old steel rims, it takes a lot of care to achieve those pressures, and it's usually wiser to use a little less air, as long as you're avoiding pinch flats.