In The Sims 3, Sims can buy a bike to travel around the neighbourhood.
To use a bike, one must buy a bike stand too. The bike goes into the Sim's inventory when they take it into town, and returns to the Sim's bike stand when they return home. Children will ride bikes to any community lot (unless they are going to school, in which case they will take the school bus) if they're going alone, even if they own no bike.
Bicycles are also one of the few vehicles Sims can use in Shang Simla. These, however, seem to be road bikes. It can be identified by the drops handle bars.
Bikes have a speed rating of 2.