It is perfectly feasible to take your bikes on most airlines, the rules and regulations do vary from carrier to carrier. Some like KLM have special bike sized cardboard boxes which you can buy for your flight for a minimal charge, some require you to bag or box your bike, others just require that you remove the pedals, deflate tyres and turn the handle bars around. You will need to check with the airline that you intend to use well before booking as if you turn up with an un bagged bike the airline may refuse to handle it!. Most of the airlines include the weight of you bike in you luggage allowance!!, so be warned you could incur excess baggage charges.
A good site for information on taking bikes on planes is 'Travel with Bicycles'.
Our first experience of taking our bikes on planes was on our 2000 tour of Finland when we flew with Buzz from Stansted to Helsinki. Their regulations were that the bikes should have both wheels and pedals removed, tyres deflated and handle bars turned around. We decided that as they required both wheels removed we would pack the bikes in bike bags.
Arriving at Stansted airport with the Bike Bags
We purchased two bike bags from St Johns cycles in Bridgewater as they seemed the biggest in size to cope with our large touring bikes and the best value. We then had the problem of how to get to the airport, we decided on the outward to go by train as Stansted has it's own terminus. This meant that we could pack the bike bags at home saving the hassle of having to take them to pieces in the airport concourse (this was the right decision as Stansted was heaving with people that day) We found the bags reasonably easy to carry although it helps to be tall! On our return journey we were pick up at the airport by mother in law with our car and the bike rack. This did involve rebuilding the bikes in the car park but then there was not the pressure of meeting flight departure times.
Our second flight with the bikes was with Norwegian Airlines to Norway in 2006, again we used the bike bags and had no problems, although the bike bags suffered a bit of scuffing but the bikes were OK. Due to the early departure times we used a taxi minibus to get us back and forth to Stansted airport, which was more expensive than the train but quite convenient as it was door to door.
The bikes dismantled in the bike bag
In order to get the bikes into the bike bags we had to remove the rear carriers, mud guards and the rear stands as well as the wheels and pedals. With the handle bars dropped and turned they only just fitted.
Our bikes weight nearly 16kg each and with our panniers we reckoned we were nearly 15kg each over our luggage allowance. We were expecting to have incurred excess baggage charges but both on the outward and return flights we weren't charged any. Why this was I'm not sure, whether it was because we had booked well in advance and that they were expecting two bikes and had included them in the pay load calculations, or that the planes weren't fully loaded although both flights seemed to be full. Anyway well done Buzz we'll let you off the minimal damage on the outward journey.
To use bike bags or not to use bike bags?
Although our bikes did suffer some minor damage on the outward journey (a broken bottle cage and a crack in the plastic chain guard), we think this was mainly due to them being opened by customs in order to have their wheels sprayed against 'Foot & Mouth' and then not being repacked properly. These are our thoughts about whether to use bike bags or not, perhaps you have other experiences in which case we would interested to know.
Using Bike bags
Advantages
Bikes are protected from rubbing against other baggage in transit.
Less risk of them being damaged.
Everything is in a bag together, Extras such as bottles & pumps etc. can be left on the bike.
Disadvantages
If airport security open them, they may not pack them back as well as we would ( personal experience as our wheels had to be disinfected during the Foot & Mouth crisis and the wheels were left against the bottle cages and broke one off.)
What do you do with the bike bags whilst you are touring?
Initial cost of bag.
Not using Bike bags
Advantages
No worrys about where to leave the bags.
Easier to get your bike to the airport.
No costly bags to buy.
Disadvantages
Bikes are at the mercy of the baggage handlers and to how well they load them.
More risk of them being damaged.
Have to disassemble at the airport and if wheels and pedals need to be removed and strapped together.
Extras such as bottles, pumps etc. can't be left on the bikes and have to be stored in your panniers.
In answer to one of the disadvantages of bike bags 'What do you do with them when you are touring', (they are too bulky to contemplate carrying them) when we flew to Helsinki we stayed our first and last nights at an airport hotel which we had booked in advance. When I booked I managed to negotiate that we could leave our bike bags at the hotel, this they kindly agreed to at no extra charge (they were stored in a locked room usually set aside for luggage).
Which ever way you chose there is one thing that you should do if you do use a bike bag and that is to reinforce the dropouts. One of the main strengths of a frame is the fact that the axles hold the forks and rear frame in tension. Without the axles there is a chance that if some thing heavy were dropped on them the frame or forks could be bent. By putting some reinforcement between the front and rear dropouts you can help prevent too much damage.
I simply bought some 8mm studding, some large washers and nuts from a Hardware store. I then cut the studding to size, adjusted the inside nuts and washers to the size of the dropouts, then tack welded the washers to the nuts and the nuts to the studding. Fitting is then easy, simply drop them into the droputs, place a washer and a nut on the outsides of the dropouts and tighten with a spanner.
Reinforcement between the dropouts to prevent the frame & forks from getting bent.