I primarily use Kelvar bead tires but have used wire bead tires in the past. Having had blowouts caused by road hazards on both I feel that the deflated tire is more likely to stay on the rim if it has a wire bead. The wire seems to give the deflated tire more structure. At least that is what I thought looking down at the deflated front tire hoping it would stay between the road and the aluminum rim. Maybe a tight fitting is what matters most. I have never seen any data on the subject.