I use 700x32 panaracer urban max tires with slime tubes from Performance bike. Have only flatted twice with this set up in over two years of 3-4 day a week commute on pretty bad roads including a short dirt section with star thisle all over it and the ever present broken glass almost every day somewhere along the way. The flats that I did get, the slime tubes allowed me to get all the way to where I was going before it was completly flat.