You have to be really careful with weight. British Airways allows 23 kg per bag, which is about 50 lbs. Other airlines have lower limits. The truth is you really don't want to go much over about 40 lbs if you can help it. The bike bag (see photos below) that I bought has backpack straps, but they aren't exactly well padded. You don't want to do more than very short walks with a heavy bag.
The main problem that I found was the weight of the tools. First thing I've got to figure out is a light weight chain whip (which you use to hold the cassette to take it off). Perhaps I can figure out a way to attach a piece of chain to the crescent wrench. Also, the nut drivers are nice to have, but they've got to go.
Because I was traveling for a two-month trip (but not all biking) I had two checked bags and a carry-on, which was difficult to manage in transit. It would be much better to have only a carry-on and the checked bike bag. Easiest way to keep weight in the bike bag down is to carry-on some of the metal stuff, but this might be difficult as the airport security might frown on a
carry-on with a bunch of strange metal pieces.
