Ok, so experimentation with the Ortlieb Office Bag 2 yielded proof of concept, but not complete success. As you can see below, the QR mount doesn't destabilize the bike significantly; it's almost as good as direct on the rack wheels. On this basis, I will not be looking at skate wheels. Also, as you can see in the second pic, when I offered the case up in the approximate position, there's plenty of heel clearance. The only problem I had was that there are two bars that run crosswise under the rack to hold the QR unit in place, and there isn't clearance on the rack for them. I'm pretty sure that in recent years I've seen a version of this unit which has, instead of 2 bars, 4 individual corner fixings, which should work well. Now for some google-fu to see if I can find one. I think the Office Bag will be GO GO GO!
