Seating the bead.
This may sound rather noobish, but I need to know if I am installing a new tire right. I bought two Maxxis Detonators to replace the stock tires. The wheels are the entry level Alex DA22 that came with the Giant Defy 3. I've flatted before and swapped tubes, but these Detonators feel very loose on the rim. The first time around I mounted the tire (hands only), pumped it up to 20psi, pushed in on both sides of the tire all along the rim and once I felt it wasn't pinching the tube, inflated to 110psi. After removing the pump I went to check the pressure with a tire gage and the tire promptly blew off the rim at the stem and popped the tube. Second time around, the tire was bulging out near the stem as the bead just wasn't seating. I've played around with it and pumped it up a little at a time and it seems to be sitting better, but there still seems to be too much "looseness" around the stem area on one side of the tire. I have not gone above 30psi yet.
Also, the bead feels pretty flimsy, I assume because the tires are foldable?