I use these on my crappy tires that would go flat just holding a nail too close. I added these and have NOT gotten a flat yet.

http://www.amazon.com/RhinoDillos-Ti.../dp/B008IXHOPA

On my way to work, I have to ride through 2 streets under road construction, then at my work they are building parking garages which means rocks are EVERYWHERE. Nothing so far....just a thought.