Ryanair

I've flown Ryanair Stansted - Girona return a couple of times now.  My bike box has come back with a few dinks and cuts.  No damage to the contents though.  Looking at the state of the box now I'm not sute I'd want to trust my bike in a soft bag to the baggage handlers.  Last time out we were sat over the loading door and I watched my box thrown by the handler onto the loading conveyor - it wasn't gentle!

Agree ref proper box, and as an alternative to a trailer, could you use bus/train/taxi at either end? Appreciate it's less "active travel" than riding to/from the airport, but ultimately, you are actually using an aeroplane for the other part of the journey. 

I wouldn't consider putting a bike into the cargo hold protected only by fabric.  You're just asking for trouble.  Consider buying a proper box, taking it with you on a trailer, packing it properly, and then storing said box+trailer at the luggage department at the receiving airport.

I've taken bikes on ryanair, never had an issue. all the baggage handling is centralised at airports anyway, so the people throwing your bike off the ryanair planes will be the same ones throwing it off any other plane

Lots of general advice here

https://road.cc/buyers-guide/best-bike-boxes-bags