Outdoor storage?

I'm thinking about storing my mountain bike outside on the balcony. Any time I mention outdoor storage to someone in a bike shop, they tell me not to do it. But I have space problems indoors so I'm wondering just how bad it is for the bike. Does anyone have experience with this?

Background: I live in a smallish 1BR condo. I currently keep two bikes in my living room - a road bike that I ride a lot, and a mountain bike that gets less use. I keep them on a gravity bike rack, similar to this one (only mine is made of oak):

http://www.bikerackshops.com/PLB-2R.html

Due to the small size of the condo, I also have my desk and computer in the living room. Which makes it not a very nice living room, and my options for arranging furniture are very limited. I think if I only kept one bike indoors, it would give me more flexibility and make the place a lot nicer. So I had the idea about keeping the mountain bike on the balcony.

Since I don't live on the top floor, there is another balcony above mine which kind of acts as a roof. It does get wet out there when it rains, but close to the building wall it usually stays dry. If I did put the bike out there, at the very least I'd get a cover for it, such as something like this:

http://www.amazon.com/Pyramid-Plasti.../dp/B000AO7GYO

So, would I be destroying the bike if I put it outside, or would it be okay?

Thanks for your input.

I can’t speak from experience regarding keeping bikes on balconies, but I do know that we had extra bikes stored in our outdoor storage shed and they began to rust eventhough they were inside the building. The night moisture is definately not good, nor is the temperature changes. We were told by our LBS to not store bikes in the garage either - our garage gets very warm in the summer and cold in the winter. So now we have several bikes taking up space in our living room as well. Not sure what to do yet, but our motto is: love us, love our bikes. I feel for you not having enough space however - hope someone can come up with a solution for you. Short of suspending them from the ceiling, I can’t come up with anything. Thanks for the link on the bike stand - I will run it by DH - that would help our situation.

I stored my hybrid on a covered balcony in Greenbelt Maryland and it rusted in no time. Not enough rust to destroy the bike but enough that I had to scrape rust off a few places.

Also, when I didn't ride it for a few months a group of wasps made a nest in the frame. to get them out I had to spray chemicals into the frame and then run back inside to avoid the hoard of wasps that were trying to defend their home. Took awhile to get them all out.