My front tires say 35 psi. Even with 35 psi they squat pretty good with a full bucket of dirt. In the winter I have my front blower on and at 35 psi they don't seam to flex much. That morning I noticed they were squatting some so I checked the pressure, about 25 psi. Because it was cold I didn't bother turning on the compressor to pump it back to 35 psi, figured 25 was fine. I removed the blower (but not the subframe) and put on the loader. I had it about 1/4 to 1/3 full of sand when the tire spun on the wheel.
If I hadn't seen it happen I probably wouldn't believe it. If I hadn't checked the pressure I would have assumed it was a lot lower than it was. Since it was cold out and my garage isn't heated I ended up taking the tire to a tire shop to have them bead it (I'm not a fan of using hair spray and a lighter). Either way I now keep them at 35 psi and have two tubes sitting on a shelf in case it ever happens again.