Originally Posted by Dean V

The Schwalbe is just a fairly loose fitting tyre. I have had trouble with it blowing off some rims as well. It is nothing to do with rim width but is more related to diameter and bead. The Michelin Pro Race in a 25mm is a big tyre and similar to most 28s, though still a bit smaller than the 28mm Ultremo. Similar weight and performance too. Michelin are also bringing out a 28mm but I don't know when it will be available.