I converted one of my MTB's to a "path bike"/rough road bike using the
Kenda Kwest Hi-pressure (100psi) 26 x 1.5". A 1.25" is available in Hi-pressure also. I live in SE Michigan in the metro-Detroit area so the roads are terrible around here with broken and narrow shoulders. When I ride unfamiliar routes or exploring new routes, I usually use my MTB with the Kwest. Then I use my road bike when I find this is smooth enough for 700x23/25C. I tried a couple other commuter/path/road MTB tires but almost all are low pressure (~60psi) and the rolling resistance was awful with an annoying hum. I really like the Kenda Kwest Hi-pressure tires. They have low rolling resistance (relatively speaking(, good wear (so far), good traction and are significantly lighter than 1.95 - 2.3" MTB knobbies.