Check the size of the elevator. We were in Seattle area and couldn't fit the tandem (Cannondale Mtn) in the elevator. It was signed for bikes to use the elevator, but the captain carried it up several flights of stairs (but nowhere close to 18 floors). We were able to stand it on the rear wheel as others described in the train, but had to hold it as the spacing wasn't right to hang it like the single bikes would fit. We haven't found any buses that would allow us to put the tandem on the bike racks, so check your transit service if you want to use the bus to get you to areas to ride. When in Denali Nat. Park, we asked if we could put it in the storage area they had on some routes, but answer was still no.
All just minor inconveniences. Hope your storage solution works out, riding twogether is wonderful.
:-)