The outward leg of this trip ends up in Athens, Greece, with a bus trip into the city at some ungawdly hour of the morning, then hanging around until 3pm when we can check in to our accommodation which is a few km from the bus station, so will probably involve another bus trip. Plus a stop over in Tokyo on the way with a couple of bus rides so mobility will be a plus. Then there's the flight from Venice to Helsinki and a tram trip into town and back out again.
I'm now planning to squeeze 5 pounds of mud into a 10 pound sack as well. I've figured out if I pull the bikes down I can fit them in a modified box that is under the Japan Airlines large luggage limit which is 203cm total, saves 20000yen , which is around US$190, per bike per leg . Sucks though, fenders off, handlebars need to have all the controls removed, bottle cages off, racks off, forks off. Wheels out, which is a bona-fide PITA with the Rohloff, which will now leak oil everywhere without the skewer in. Box ends up being 76x21x105cm. But for $380 extra each way I'll do it. At least there's so little room in the box nothing much can move around.