Why is the "free flight bird" more important than the bikes? If "free flight" is important, then the free-ist flight is not to be caged by humans. (But I'm sure you've had this conversation hundreds of times, so never mind me.)

Having said that, I would submit that you are probably stuck with constructing a shed for the bikes (constructing a shed for the bird will not, dare I say, fly). While you are building the shed, assuming you are using one of the ready-made versions available at the equivalent of Home Depot, etc., I would place an eye-bolt in a concrete anchor inside the shed so you can chain your goodies up.