I have Panaracer Pasela tires 27x1” and 27x1 1/8” . They offer a TG version which has a bit more protection from road hazards . TG is Tour Guard. They are nice riding tires , but they do have tread. I don’t notice any roughness to the ride and I am running at 85lbs on the rear and 80lbs on the front. Joe. joesvintageroadbikes.wordpress