I tried Schwalbe Blackjack 1.8 three years ago when desperate for a narrow rear tyre for a winter ride. Not aggressive but roll well, fairly heavy but cheap. They worked really well except in extreme mud. I've now got all my rides on these though the latest I've bought are 1.9s s.I think Schwalbe have dropped the narrower ones. Now running the 1.8s on the back and 1.9s front.