Originally Posted by John_V

I run 25c Gatorskins on my 4 year old, American Classic, tubeless ready, aluminum rims. It's the only tire that I use. I was having the same problem as the OP sine the day I got those wheels, especially with new tires. It got so bad with one set that I ended up taking the wheels and tires to my LBS to see if they could get them mounted. I then watched my mech install both tires, by hand, as easy as if they were being mounted on clincher rims. Then he told me what he did and I followed that advice on the last set of Gatorskins I mounted and damn if it didn't work. The only difference was that I had to use a tire lever to pop the last section of tire on the wheel since my 73 yo hands aren't as strong as his thirty something hands. What he did was to continuously move both sides of the tire toward the center as the tire is being mounted. All I can say is that it worked. If you've already tried that and it doesn't work, your wheels are much more of a PITA than mine.