Hello, we are a family of four biking across America. I am interested in this thread, because we bought Schwalbe Marathon Plus tires to replace what we were riding on. We replaced them in Pensacola, FL, and have had several flats on them coming west. A few were my fault, due to walking our bikes through goat head thorns (ACCIDENTALLY)!

We have had several due to the small truck tire wires. I was under the assumption that Schwalbe tires by themselves would do the trick, but they haven't. In fact, I am running one Walmart Kevlar, and it has held up better than the Schwalbe's!
I know this sounds blasphemous, but it is the way it has happened.

Please give advice!