Here's the short version:
- Regardless of whether the airline has a limit for the size of a bike box, pack the bike as compactly as possible so it will fit in the various trains, cars and buses you're going to use.
- The TSA will unpack your box, so make it simple to repack.
- It used to be different, but these days the airline's bicycle fee keeps you from having to pay the (much higher) oversize bag fee. If the box is overweight, you'll pay an additional penalty.
- Apparently flying with a bicycle remains unusual enough that you're likely to run into a airline employee who is unfamiliar with the process.
Do you want to bring a bike?
The first question to ask yourself is whether you want to bring a bike at all. You could, for example, rent a bike. I was under the impression that it's hard to rent a road bike in France in July, but my wife found one in Paris easily enough (I would have needed it in Grenoble). Obviously you're limited in choice and likely to get a lower-end bike, but in my case that would have been fine. It would likely have been cheaper, and vastly less hassle, to rent.
Another option I considered was buying a bike, likely in Grenoble, then selling it for whatever I could get in Paris. This would give me a little more choice, and since I'd be looking at relatively low-end bikes probably wouldn't cost much more than the other options. But that's a big "probably"; I have no idea where to sell a bike quickly, so if I got 50% of the purchase price I'd consider myself lucky.
Boxing the bike
Since I settled on bringing a bike (with one of the other options as a plan B, if my bike were lost or damaged), I needed to box it. People who do this a lot buy dedicated containers, but since I would be touring partly by bike alone, I either needed something disposable (ie cardboard), or I needed a place in Grenoble to store a bike case for 10 days. Cardboard it is.
Searching online, it became clear that Air France would sell me a box. But when I called them, they said they would only sell me a box immediately before my flight, as I was checking in. That hilariously silly policy may have been a figment of some customer service drone's imagination, but in any case I wasn't willing to put off packing anything, let alone the bike, until the last minute.
Amtrak sells boxes, as it turns out, so we visited the local train station. They had a used box that they gave me for free. This box was giant, and entirely unwieldy. I'm not sure whether there are size limits for bike boxes on airplanes, but this box was just too big to lug around. I ended up cutting off the side of the box and turning it sideways, then cutting off the opposite end and using it as a removable top. Since I knew the TSA would have to open the box, I bought nylon straps to close it, instead of tape. The box ended up measuring 46x29x11 inches.
To pack the bike, I removed the pedals, seat and wheels, then removed the skewers from both wheels. The pedals and skewers went into a ziplock bag. I then removed the handlebars and the forks, and the rack from the rear. The bolts went back on the bike, the spacers into the ziplock. I put some paper padding in the box, wrapped some of the dangly bits on the bike, and stuffed it in. Then I squeezed the wheels and seat in, and found a place for the ziplock bag. The hubs of the wheels formed the widest part of the box, so I made a couple of columns of cardboard to support those areas, and arranged them among the spokes.
The cool thing is that, on my bike, I could do all this disassembly with just three hex wrenches: 4, 5 and 6 mm. And since I happen to have a Y-shaped hex wrench with those three sizes, I could disassemble and reassemble the bike with one tool.
Flying with a bike box
The first test of the trip was getting the box to the airport. We took a SuperShuttle, and because we had lots of luggage but especially because we had a bike box, we had a van to ourselves. Had my box been much bigger (like, say, the original Amtrak size), there's no way it would have fit. I could just barely squeeze the box into the van sideways.
When we got to the airport I found that the box was about 33 pounds, which was well under the lowest airline limit of about 50 pounds. My first leg went from San Francisco to New York on Virgin America. They charged me $50.
While I was in New York I rode the bike a few times, partly to figure out whether everything was still working. If it was broken I'd certainly prefer not to pay to bring it to France. What I found when I opened the box was that while everything had survived, the TSA had repacked the whole thing quite carelessly. One of my hubs had punched a hole in the box itself, but there was no damage to the bike. The lesson I learned, but have found difficult to apply, is that however clever your packing job, one important factor was making it easy for an indifferent employee to repack, without instruction. I certainly didn't master that, but the next time I packed the bike I made it much simpler.
Delta charged me $75 for the flight to Paris, and the bike miraculously appeared among the odd-sized luggage at Charles de Gaulle Airport. Getting to our first hotel, near the airport, just meant getting the box on an airport shuttle, which was no trouble. The next day, I had to catch a train from Paris (Gare Lyon) to Grenoble. We rented an Opel Meriva, which again could just barely fit the bike box in back, after we lowered the rear seats.
When I booked the train tickets, I specifically chose the 3:37 PM TGV train to Grenoble because on the booking web site there was a little bicycle icon next to that particular leg. I have no idea what that meant, even now, because the train had no special accommodation for bikes that I saw. The train had a small luggage section in the middle of each car. I had hurried to my car as soon as I could, and when I got there the floor portion of the luggage rack was still empty. I took up the whole width of it with my box, then found my seat before anyone could associate me with it. No one asked about it. I have no idea what I would have done with either a larger box or an unboxed bike.
This box's lifetime ended in Grenoble. The next day I left Grenoble on my bike, with no ability to carry the box nor anywhere to store it in Grenoble. I therefore left it in the hotel room, along with a 10 euro tip to partly make up for doing something so rude.
Carrying the bike around France
My general plan was to do a loop of the Alps near Grenoble, then drive down to Mont Ventoux. So after 10 days on the bike I returned to Grenoble, rented a car, and drove to Carpentras.
The car was a Ford hatchback, maybe a Fiesta, and the bike fit easily. If I remember correctly, I didn't even have to remove the front wheel. After Mont Ventoux I drove up to Tours to meet the rest of my family, and then a few days later we all drove back to Paris.
For this leg of the trip, I needed some way to carry the bike. It wouldn't fit inside the car, since there were now three kids and all of our bags. I gave some thought to just lashing the bike to the roof using those nylon straps from the box, but that seemed embarrassingly jury rigged. If I had been alone I would have done it, but not with the wife and kids looking on. I ended up visiting the one bike shop in our village, which had exactly one bike rack for sale. For 70 €, I was set.
In Paris, the bike spent all of its time locked up. I cycled in Paris quite a bit, but always used the rental bike system Velib, which was much more convenient.
When it came time to come home, I needed to find another box. Again, I could have relied on Air France, but I didn't want to leave it until the last second. So on the day before we left, I visited the nearest bike shop (directly across the street), and asked if they had a bike box they could spare.
Or at least I tried to. I used the word boite, which might translate as box, but it's not the right concept. The right word is carton, which means cardboard or a cardboard box. They didn't have one; they routinely cut up their boxes and store them flat. They pointed out that all bike shops in Paris do the same thing, since they're all short on space. What they had were very large flat sections, perhaps 5x3 feet, which they were happy for me to take away. I took four of them.
OK, I was getting closer. Earlier I needed a bike box. Now I just needed tape and a knife. As we all emerged from the subway I told my wife I was going to look for an appropriate store, but before I even took a step I saw an Office Depot. Problem solved!
I used two of the flat sections to make U-shaped box halves, which I taped together. I made a removable top from one of the other pieces. I had nothing to measure with, no straight edges, and was constructing the thing in a small apartment. It turned out not quite square, but it stood up on its own. I was pretty happy with it; my daughters were not impressed. The bike boxes (Giant brand boxes, incidentally) were double-thick, and because the way I made my box the bottom and sides were quadruple-thick. This box was incredibly strong, and slightly larger than the first one. The bike therefore fit pretty easily, and I threw in my 70 euro bike rack, too. It came it just under 20 kg, well under the 23 kg limit (and lighter than two of our other pieces of luggage).
We had a van bring us to the airport, and once again the box just barely fit.
When we got to the airport the Air France ticket person wanted to charge me 300 € for an oversized bag. I said out that the proper price was 75 €, and indeed I had to show him the Air France baggage page on my iPhone. He fetched a supervisor, who corrected me (it was actually 105 €, since I was travelling to Zone 3; the relevant page had been a 404 when I looked at it) and showed him how to enter the information on the computer.
But that was only part of it. I would have expected to pay the fee and move along, but it turns out that despite demanding payments at that counter, they don't accept payments. He printed me a voucher, to pay at the automated check-in stand. Then he said that he couldn't take the actual box -- I'd have to carry it to the other side of the terminal. Then he said I should put it on a cart behind me, and leave it there. I walked away with the voucher and zero expectation of ever seeing the bike again.
I tried to pay at the automated terminals, but couldn't make it work, even with help from an employee. He then told me I'd have to go wait in line at the ticket office, on the other side of the terminal. It was at this point that I started wondering what would happen if I didn't pay the fee. But rule-follower that I am, I dutifully waited and paid.
When I saw the bike box appear in the oversized bag area of SFO, I was relieved and quite surprised. To get home we once again used SuperShuttle, and wouldn't you know it -- the bike box just barely fit.