I recently upgraded my Kona Crosstrail to
Schwalbe Marathon Supremes 700x32c. I found myself riding mostly on the road with my bike and wanted efficient tires. I get an average 2-3 mph faster than with the stock 40c tires with more tread. These tires are very road efficient yet still have a little bite on dirt roads and paths. Another plus is they are very flat resistant. Amazon.com : Schwalbe Marathon Supreme RLX Folding Bead Tire (700X32) : Bike Tires : Sports & Outdoors