I recently posted ("Recalcitrant Tire") about my dismay and frustration at a set of Avon AM-26 tires resisting my attempts to mount them on my V50 wheels. Windex and dish soap had their chances and failed. The front tire, which I had thought correctly seated, on closer inspection proved to be asymmetrically seated, just like the rear. All efforts to seat the resolutely defiant beads, including letting the tire sit overnight at 102 lbs of pressure, proved futile. I even tried some GoJo hand cream, recommended by one member with the intriguing description "slick as puppy snot". Sorry puppies, no joy.
Lannis and several others declared that Ru-Glide or other dedicated tire lube would be the solution. Out of alternatives, I ordered a gallon of Ru-Glide. I levered off one bead of each tire, copiously lubed up the beads and wheel shoulders, remounted the beads and hooked up the compressor. At about 60 lbs., the rear tire gave up resistance, quietly squeezing into a complete, symmetrical seat all around without any drama or thunderclaps, just slipping silently into position. Front tire the same - all good, resistance quelled. Thanks for the cogent advice.
Now I have a lifetime supply of Ru-Glide and you can count me among the True Believers: Real Tire Lube is the way to go, all else is just an imposter.