Camilo

So what I'm reading here and from the manufacturers is that the common way of hanging from the ceiling by both wheels (in other words, horizontal, upside down) is not optimal for hydraulic disk brakes, maybe even causing air bleeding problems in an imperfect world?

That's the only way I can store the multitude of bikes we have in our family.

JohnJ80

Isn’t an issue. Mine are hanging so they are within inches of each other. You can also adjust the straps such that the seat or handlebars touch the ceiling when pulled up tight. You do have to properly align the eye bolt it hangs from so that the bike is aligned accordingly.

If they did swing around, I’d have a big mess because of how close I have them mounted.

A benefit of this hanging method is that you can turn the bike as you lower it. I have mine mounted so the cranks are just forward of the bumpers of our cars. I can then lower the bike and turn it 90 degrees as it descends so it is parallel to the front of the car. That way it’s easy to get any bike out of the garage even with both cars in place.

Andy Somnifac 

You're telling me. I have one I want to get rid of...

Andy Somnifac 

I have 6 bikes hanging in 48" of space. They will live if they touch each other a bit.

eduskator

As other said, the only potential issue of hanging a bike upside down are the hydro brakes because of the reservoir in the levers. Otherwise, it's fine.

Bikes are made to withstand body weight up to 250-300lbs, they can be hung vertically on a wall (that's what I do) or from the ceiling from almost every components (I wouldn't try the derailleurs though!)

Moe Zhoost

They come alive if they touch? Do they make babies?

Mojo31

You wish!