150x80x20= 250 (cm)
It seems impossible to respect 158 cm lxLxh
Now i understand the interest to have s&s couplers ...
I have flown twice with my S&S case, once with my Nomad in it. The couplers are expensive and so is the cost of a case. I built up my Nomad in 2013 and finally this year I expect to finish my attempt to recoup the costs of couplers and case in airline savings.
But, I find one of the biggest advantages of the couplers and S&S sized case is that it is much easier to take a taxi to an airport, in my community most of the taxis are Prius and a big bike box is much harder to get to and from the airport.
My next trip, I take a taxi to a bus stop, take a bus a couple hundred km to an airport, take a motel shuttle to a motel for the night, next very very early morning take the motel shuttle back to the airport to get on a plane, at next airport pick up my luggage and go through customs, re-check the checked bags with bike in one of them, at next airport get on a bus, at the next bus stop carry my luggage about three blocks to a hostel where I will assemble the bike. It will be a very inconvenient 36 hours with an S&S case, but with a full size bike box I probably would have decided to stay home instead.
My luggage for the previous trip with the Nomad on a plane in the photo. The large black case is the S&S backpack. I wear my helmet onto the plane so it does not get crushed in the luggage.