Your local bike shop will probably give you one of these for free if you ask, and they may even throw in a bunch of packing materials.
Keep in mind, though, that these boxes come in different sizes. If your bike is of the longer travel variety, or has a larger frame, 29 inch wheels, and/or larger volume tires, it probably won’t fit into a smaller box. Tell the shop employee what bike you’ll be stuffing in the box, and they should be able to point you in the right direction.
It’s a cheap, easy method. But the cardboard box is not without its drawbacks.
It takes a lot of time, effort, and expertise to pack a bike properly in one of these boxes, and failure to do it right is very likely to result in damaged goods. Most bike shops will do it for you (for a price), but if you choose this option you’ll probably also need someone to put it back together when you arrive at your destination. Then you’ll have to do the whole process over again for the return trip.
On top of that, airlines will generally not cover damage to bikes in cardboard boxes. The only way the airlines will cover any damages is if the bike is packed in a bike specific “hard case,” and there is also obvious damage to the case that correlates to the damaged area of the bike. Or if the bike is improperly repacked after inspection by TSA.
It’s also a real pain to lug a big box around the airport.
Overall, the bike box is an easy one-time option. But it gets real old real fast if you travel often with your bike.
The “deluxe” option: The hard case
At first glance, hard cases seem to be the Cadillacs of bike travel. And in many ways they are. But these sturdy plastic cases have drawbacks of their own.
For one, they’re small. It’s basically impossible to transport a modern downhill mountain bike in a hard case (though smaller road bikes often fit). I’ve used hard cases in the past, and almost always had to carry some components (usually the fork, seat, and seat-post) in my other carry-on bag. This means additional disassembly and reassembly of the bike as well as added weight and perhaps additional charges for your other bag.
TSA will almost always open up your hard case and pull most everything out to inspect it. In my experience, they almost never repack the bike properly. I’ve now had two bikes damaged because of this.
The cases come with external wheels, latches, and handles. Which are great… until they come off. You can pretty much count on these being smashed off after a few trips, and airlines won’t cover damage to the external features of any luggage.
And once the case is damaged, the airlines will usually have you sign a document stating that the case was already damaged when you check in at the airport for departure, and therefore, they will not be liable for any damage to the contents.
This obviously negates the whole reason to use a hard case. A major bummer since they cost $400-500.
In summary, hard cases are not my favorite option (could you tell?).
The preferred choice (for me): the bike bag
My travel method of choice for my bike when I fly with it, as well as that of most mountain bikers who log plenty of miles flying with their bikes, is the new generation of “bike bags.”
I love these soft cases for their ease of packing, minimal bike disassembly, relative ease of navigation through airports, ability to pack down during storage and transport when not in use, easy TSA inspection (bike and components don’t have to be removed), relatively good protection (which we’ll improve upon with extra packing), and durability.