Originally Posted by
Herzlos
So basically the tyre sits inside the rim diameter and with a stiff enough sidewall (potentially aided by pressure) it can't come off without some external force?
It's more about the bead diameter and the bead not stretching. If you look at the hookless profile, on the right, you'll see the center well and, on either side of that, the bead retaining humps and then the bead shelf. When installing, you're getting the beads in to the middle well, which gets you more room (smaller effective diameter) to get the tire on. When you hit it with air, the hooks slide up the sides of the well (which is why bead lube of some sort is helpful), over the humps and snap in to place on the bead shelfs. You should be able to imagine how most hookless tires, even without air, will stay bead-locked.
