My Co-Mo Mocha came with Schwalbe Marathon Racers and we have used them for 5 years and like their durability and have had few flats. The following small ruts may be from the narrower tire as I notice that more on our 700 C tandem. I understand about the road tandem, I do see a difference in our speed between the 26" and the 700 C tandems although we often take the Mocha when we ride alone.