Joined: Nov 2018
Posts: 724
Likes: 510
From: Redmond, WA & Bangkok, Thailand
Bikes: 1999 Giant ATX MTB, 2002 Lemond Zurich, 2018 Fuji Transonic 2.3, 2019 Specialized Tarmac Disc Expert
Just hoist that bike up on one arm and take the bike up and down the stairs. Use your free hand to guide the front wheel around corners if you need to. Consider it cross training. Pretty soon you'll be so adept at it you won't think twice about it.