I rode tubulars back in the day when I lived in central Texas and, best I recall, goatheads were not a problem. Usually Continental Sprinters. But even so, when I got a flat it was a real big bummer, so I eventually moved to clinchers.

The memory of tubulars lingered, but many years ago I moved to goathead country. If this means little to you, just know that in the fall I can easily pick up 2 or 3 punctures per 50-mile ride, more or less. So I never seriously considered going back to tubulars.

But then I decided to get my Pinarello back on the road, which meant trying tubulars again. Then I learned about Tufos and their sealant. Now, with maybe 1,000 miles on them, I realize that I had it wrong for years. I cannot say anything about sealant for non-Tufos (Tufo tubulars are made differently in ways that facilitates effectiveness of their own brand of sealant). But for Tufos, which I run pre-loaded with a small amount of sealant, goatheads are about the least consequential road debris out there. I usually have no idea I've even picked one up. I can flick them out of the tire and the sealant takes effect almost instantly.

Get this: I no longer carry a spare at all! And being tubulars, no patch kit either. In goathead country.

To answer your question: the S33 pro. Tried different pressures, settling on 100 PSI. Measure about 24 mm wide.