I dont have a case to offer, but just wanted to share a travel idea that someone else I know has tried and used successfully;

He has found a way to get his (size Xlarge specialized epic) full suspension mtb to fit into a hard suitcase (no oversize or "bike" charges at all) obviously, it requires a full suspension bike, and a bunch of tools and your time at either end of your trip...for him, it saved a lot of money, since he was traveling with his bike a lot.

Here's what he does. Takes the seatpost, fork/bar/stem, the whole rear swingarm assembly & the shock off of the frame. Takes the skewers out of the wheels.
Everything gets wrapped and carefully packed into the case. Smaller bits go into separate bag. It goes right through as regular baggage.

Of course, with the recent airline fees going sky high for regular checked baggage, I dont know if this still saves money...