Dia Compe 981 canti's, which came on some 80's Schwinn Voyageurs, will adjust for both 27" and 700c wheels. Tons of room for big tires, even with fenders, and every braze on imaginable. Three H2O bosses, front and rear racks, and fenders. I have a Voyageur SP set up as a dirt road bike with Conti Cyclocross tires, and it's a blast.