Though not original to my bike, I'm running the same Weinmann 1-1/4" rims on my GJ, with 1-1/8" Paselas that I've run at 90-100 psi with no tube blow out issues between the tire and the rim. I did have a failure of the tire itself though, the sidewall separated from the bead, and I walked the bike home from that one. Since then I carry a spare tire as well as tubes.
Keep in mind, the force attempting to stretch the bead off the rim is proportional to the pressure, and to the square of the cross-section diameter.