Flying with your Di2 bike is very much like flying with a regular bike - there are just a couple of differences and extra bits to think of. Let's take a look at things to keep in mind when flying with your bike.
1. You'll need a bike box, case or bag
This may be obvious, but you need a way to get your bike on a plane. Without breaking the bike. You'll need a bike bag, a hardcase bike case or simply a very sturdy cardbox box. They not only differ in weight and security, but also in size and ease of use.
Which option is best for you depends on how often you fly with the bike. If you hardly ever take your bike on a plane then it's probably best to spend a little more time to take your bike apart and put it in a cardboard box. You can usually get these for free at your local bike shop - they'll have boxes left over from the bikes they have built recently. Bring some extra tape to the airport with you, just in case you need to cover up any holes or strengthen weak spots in the box.
Do you take your bike on the plane more often? Like every month or so? Then get a nice and sturdy hardcase bike box that'll quickly let you package your bike without too much hassle. These are relatively heavy, but usually the most user friendly.
Bike bags are somewhere inbetween a carboard bike box and a case. They are only slightly less sturdy than the hardcase boxes, but weigh a lot less. This can be important if your airline charges extra for heavier luggage.
2. Take some tools and parts with you
Putting the bike back together is easier when you have the right tools with you. Some basics are:
- Torque wrench
- Size 3, 4, 5, 6 hex keys (or torx, if your bike uses those)
- spare inner tubes
- The Di2 TL-EW02 Cable plug tool (not essential, but very nice)
3. You may be required to take out the battery
Whether or not you have to take out the Di2 battery depends on the airline. Some will refuse to take the bike if the battery is still installed and others will not mind at all. You will have to mail / call / bug your airline to give you an answer on this. If you can, get their response in writing. That way you can take this 'proof' to the airport with you - it may come in use.
Now.. you could just not tell them there is a battery in your bike, but would you really want to? And what are you going to do if they find out and force you to take it out on the spot? Or refuse to take the bike?
Taking out the battery is usually really simple - on most bikes it is installed in the seatpost.
There are exceptions though... on some Canyon bikes the battery can only be accessed after taking out the press-fit bottom bracket. They do this on all of their VCLS seatpost bikes - there simply is no place in the seatpost because of the leaf spring design. Here is a video on removing Canyon Di2 batteries.
Need to take out your press-fit BB to get to the battery? Then take the right tools with you to press the bottom bracket back in at your destination.. and to remove it when you fly back home.
If you have removed your seatpost battery use some tape to stick the now expost E-Tube wire to the frame - you don't want to have it fall down the seatpost and then frantically shake your bike to get it back out. The same goes for any wires you disconnect - tape them into place just to be sure they won't move.
4. Unplug some Di2 components
Even if you do not have to take out the battery it can be worth it disconnecting it anyway. At the very least, disconnect your shifters or simply unplug your junction A (if you have the older below-the-stem junction).
You do this to make sure the bike doesn't try to shift while on the plane - this could easily drain your battery during the flight. When you get to your destination you probably just want to ride your bike, not charge it first.
5. Take your charger
Technically the charger is a 'part' and I could've mentioned it under #2... but it is a special case and definitely worth discussing on its own. Whatever you do - take your charger. If your battery runs out of charge for whatever reason you'll want to be able to charge it. Take an adapter block as well and keep in mind that it should supply at least 1A.
Don't forget the other essentials such as shoes, helmet and other clothing... and have a nice trip! Flying with a Di2 bike isn't all that different from flying with a non-Di2 bike. If you think I missed something or if you have any questions or suggestions please let me know.