My wife toured last summer on her Trek 7.5 WSD over many miles of the crushed limestone canal paths, Hennepin canal, Hennepin Feeder canal and the I & M canal. We did as you did and got her a stronger rear wheel and kept her rear load reasonable. One nice thing about that bike is it will accept larger tires and if you are willing to drop $100 on a front rack, try the Old Man Sherpa. Or for a $100 buy a steel fork and standard front rack as another option if you really need the carrying capacity.