My bike came with Continental UltraSport's which has no flat protection at all, and I finally got fed up with fixing flats every week or two for over a year now. I had narrowed my choices to GatorSkins, Krylion's and Lithion's, but my LBS recommended Serfas Seca RS over the Krylion's which he also had. I looked at the review sites and all the reviews of the Serfas were extremely positive, so I am giving them a try.