If you're relying on the saddle to absorb the bumps, then those tires are probably more than sufficient. I have a sprung saddle on my commuter and 26 x 1.75" tires, though as soon as they wear out, I plan to upgrade to a much wider tire for better shock absorption in the front and a narrower, unsprung saddle. The springer saddle causes me to bounce around and I feel that it wastes energy. Just a matter of personal preference of course.