Our teenager is headed off for college in 5 weeks or so. I have been fixing up his Jamis Trail X1 to be used as a campus bike. Today's tweak - and I have no more on my list - was attaching the QL3 mounting system for his Ortlieb Office Bag. It's a Topeak Explorer rack he has on the back.
I tried a few configurations and ended up with the bag hanging quite far off the back of the rack - his heels just clear: