My apologies. The TUFO tires I have had trouble with in the past were regular clinchers like the Vittoria EVO tires. There is no cross section view on the web site but they look like a hybrid between a clincher and tubular. I guess the tires in question have some kind of casing that hooks on to a clincher rim vs. gluing a traditional tubular. If you have to carry around some kind of flat sealant, to me, you might as well go with tubeless tires. At least if you get stuck you can put a regular tube in to get back on the road.