One airline you definitely want to avoid when traveling with a bicycle is Turkish airline. Happened to a friend flying from Europe to Vietnam. Paid the sports equipment fee of 150 € 75 per leg,
At the airport they told him the fee had just doubled .He had no choice but to pay an additional 150, or they would have refused to check in the bike.
4 weeks later, he arrived back home, but his bicycle did not. Was told that it was still in Istanbul. After 4 days calling Turkish Airline numerous times, the bicycle was finally dropped at his doorstep, totally wrecked.
Turkish refused to pay compensation. Months later, he has hired a lawyer and gone the legal route. The lawyer is probably gonna cost him more than the cost of the bike, but he is mad as hell.