I have been running two pair of Vittoria Randonneur Pros, 35 mm on my Surly Steamroller and 40 mm on a Surly Karate Monkey. I have put approximately 3,000 miles on these tires and have yet to experience a flat. I am a pretty careful rider and don't get many flats, but I've never had a run like this. These are mostly commuter miles and I find the ride comfortable and stable, even on our icy winter roads.