I wonder if they're selling out of the 58's with the spring training fever. I have a friend who can only find 58s and needs a 60. Frustrating! And we're on the wrong coasts to swap shops! Make sure as Melissam said to be sure the measurements are taken on the same place on the bike and then compare the measurements from the websites. You'll get an idea of what size Bianchi you need and then you can always call around.