Well, that's what I thought, but the dimensions are in the comments to the dropbox photos - all the photos have comments about the bike, so check them out if you didn't notice them before, as there are some interesting things mentioned.

The dimensions of the first case are 26" x 26" x 10", and those of the second case are 28" x 20" x 12" according to the comment, which is basically a full-size suitcase according to Delta Airlines baggage info page (here): "Baggage size must not exceed 62 inches (157 cm) when you total length + width + height". However, I'm not sure how strict most airlines are about slightly oversized luggage as long as it's within weight allowances, but it is a worry, as they might just use it as an excuse to make your pay another fee.