I'd suggest trying IRC's.
I have had unpleasant experience with the Pasellas unseating off some tandem rims (not Araya 20A's).
I think the beads on some of the Pasella tires simply tend to be on the large side.
Hugh Enox
Subject: [CR]Good tires for Araya 20A rims?
> Tim,
>
> I have the same rims on my Centurion Pro Tour. When I installed the
Panaracer Pasellas after the restoration I had the same experience. The
tubes were pooching out between tire and rim and I barely got them deflated
before they blew.
>
> I reseated the tires and now pump them to about 80 psi and no problems
whatsoever. Those rims have a reputation for not holding tires. Too bad
because they are a nice eyeletted rim.
>
> Jay Sexton
> Sebastopol, CA
>
>
>
> Date: Wed, 26 Jul 2006 23:19:00 -0400
> From: "Tim Fricker" <tymncycle@gmail.com>
>
> Subject: [CR]Good tires for Araya 20A rims?
>
>
> Okay, since someone asked about tires for a Module E, I figure it's as
> good a time as any to see if anyone has suggestions for currently
> available tires that work well on the old Araya 20A rims I have on my
> Centurion Professional. They are about the same width as the Mavic
> Module E, but the key difference is they don't really have much of a
> "hook" to them. I've tried my preferred tires, the Panaracer Pasela,
> both old and new style, but they climb right off the rim when fully
> inflated, and the tube blows out.
>
> So who has found a good, high quality, reasonably high pressure tire
> that works on these puppies? Preferably tan sidewalls, preferably
> 25-28mm wide. Anyone?
>
> Thanks!