This concerns a hazard to sidewalk cycling. I never considered this risk, and I have never seen it mentioned here. This happened a couple weeks ago.

My apartment is on the second floor above a retail bakery. Every time I ride, I carry my bike down the stairs and out the door, which opens directly onto a 5 foot sidewalk. I always just slowly nosed the bike out the door with no problems, thinking mainly about the possibility of pedestrians and shoppers coming out of the bakery.

This time however, a guy on a bike was whizzing down the sidewalk. I guess he ws going too fast to see my front tire emerging from the doorway. I heard the bike, and the guy going "WHOA!" I pulled my bike back fast enough that he barely brushed the front tire. He also swerved to the right and almost ran into the lamp post.

If you ride on the sidewalk, watch out for the doorways of both the cars and the buildings. They can get you on either side!