It goes on the sides of the second wheel, the second person stands on it and hangs on to your shoulders. That way two people can go on the bike. What's it called? What's the name?
What you are talking about are called pegs. The purpose you state is not what they were made for. They are made for doing tricks on the bike by the rider. A bicycle with one seat is made for one occupant and may be ill handling with extra weight on the back. Although you probably wouldn't get a ticket or anything (hardly enforced), it is technically illegal to have 2 people on a bike made for one.
