I recently updated the Surly Cross Check drivetrain to create a double dingle. 42t and 40t chainrings up front, 17t and 19t dinglecog on the rear. With the same chain I can run a 40×19, 42×19, or 42×17 giving me a gear range from 57.2 gear inches to 67.1 gear inches with 35 semi slick cross tires. I need to remove the fenders and mount up some Ritchey Speedmax Cross 40s to get a bit more tire under me for some trail riding. Perhaps a bikepacking S24O this fall?