Hi~

When I was rehabbing from a pelvic fracture last year, I changed out (well, my husband changed out!) my 2" or so knobby MTB tires for some slick "city" tires. They were either 1.5" or 1.75", probably the latter. I used them so I could ride my MTB on the trainer since it was a lot more upright than a road bike for rehabilitation. I later rode them on the road briefly when I was still recovering, and they worked great for that and were much faster than the wider knobbies. So, sounds like what you might want to look for is 26" city/urban/commuter tires.

Good luck!
Emily