I am not afraid of the BTC couplers, I,ve heard a lot of good reviews about them. What I was asking was if I could use instead of a steel frame fitted with BTCs a double suspension frame. I mean, is the same principle, to have your frame in two separate parts. Obviously you can not do that with a hardtail. If I were able to fit the front triangle of a size L frame of a double suspension frame on case of (26x26x10) like the one from sandsmachine it would be great. Moreover, as most of airline companies allow you to take two cases, so in case that things get too crowded in the other case you can put the rear triangle in the other case. I like the idea of BTCs but the other option is much more easier ( as long as the rear triangle is not too much complicated to dismount) and I guess way cheaper.
Thanks to everybody,