I commute with my OCR2 back and forth to school. The tires are 700x20 airless and all is well. I had a set of 700x28 on the OCR2 until “flat-town” started. The question is what type of tire size would be best suited to tour on the C&O from D.C. to Pittsburgh. I know they will be of the airless variety with a PSI rating of 110.