I would add that you can transport your bicycle on the Metro but not when trains are crowded. I would say non-peak hours are best. Also, the first and last cars tend to be least crowded so they are the best for transporting a bicycle.

This is more of a tip, but I detail here how I secure my belongings to my body. At this point, I have a good waist bag so I just attach it to the zippers on the waist bag.

Also, if you see a crime taking place, you can text MyMTPD (696873).