A friend recently flew from SFO to Italy (Milan Malpensa?) on Lufthansa. He rode to the airport and rolled his bike up to Lufthansa check-in and handed his bike to them, no hassles. Did the same coming back from Europe to SFO. His only other luggage was a carry-on duffel, which was everything he needed for 3 weeks of bike touring (mostly camping with occasional hotel stays)