It's worth your time to read the specific sections of the online "contract of carriage" for the airline you will be flying. I noticed quite a few airlines do now accept folding bicycles (no additional charge) as long as you meet their usual size (62"), weight (50lbs), and protective packing requirements (usually boxed or hardcase). IMHO, the benefit of an honest disclosure of contents might be the airline's full insurance coverage ($5k?) of the bike, should it be damaged in transit.