I should clarify my first post.
I'm referring to kevlar's greater tensile strength than steel. When used as a tire bead, once it takes its shape (diameter), it'll keep its shape and not stretch and blow off a rim as a steel bead would at greater pressure. At the time, most all the 27" narrow tires maxed out at 95 psi when constructed with a steel wire bead. With exception to an IRC tire rated at 100 psi. (But that was a crappy performing tire!)
Kevlar beaded tires were rated up to 110-120 psi. It could withstand the increase because it didn't deform.

Of course, I'm using these on hooked rims.