Ah - thanks.

Just for clarity in case I have you thinking about this on different lines to me, I'm certainly not proposing to tow the case behind the bike - LOL. No - certainly not. I was just thinking about moving it around airports or their environs. As far as the touring, I envisage carrying the case containing the contents of my luggage back pack on the rear carrier of the Merc (which is a Brompton Clone). I see the case attached at the bottom on the rack and at the top under the seat fastened to the seat post. For low drag, I suppose I'd be thinking about mounting it sideways on. If that isn't possible, flatways on, but that would present a fair old sail to the wind when riding. I have experimented with carrying 70 litre backpack on the rack. I fastened a two foot (60cm) alluminium rod to the rack extending sideways with about 8 inches protruding at 90 degrees to the wheel line on either side of the rack. I did this by whipping it to the rearmost cross piece on the rack. This meant that I could securely attach the base of the rucksack to the rack. Then I tied the top of the rucksack to the seat post right under the seat. This worked fine. Now,thinking about air travel and foreign touring, I need a way to get the bike safely across the air segment of the trip and then a way of carrying my necessary luggage on the bike. If a suitcase can fulfill both requirements, that'll be great. I could just pack the rucksack into the case complete with its contents and mount the case on the bike.

That's the idea anyhow.

Cheers.

Edit ->

Of course I could also try and copy the Bike Friday trailer idea. That has a set of wheels and tow bar that dismantle and pack inside with the bike. At the other end of the air journey, you just assemble the trailer chassis, pack the case with your belongings, which presumably you put in the hold in a soft bag, and ride off into the great blue yonder.