To understand why a two-wheeled vehicle that can exceed **45 kilometers per hour** is a **motorcycle**, it is important to know the definitions of the different types of vehicles.

- **Motorcycles**: These are two-wheeled vehicles that must meet at least one of these two characteristics: have an engine with a **displacement** greater than 50 cubic centimeters or reach a **speed greater than 45 kilometers per hour**. This means that if a two-wheeled vehicle can exceed 45 km/h, it is classified as a motorcycle.

- **Mopeds**: They can also have two wheels, but they have **low-power** engines and cannot exceed 45 km/h. Therefore, a vehicle that exceeds this speed cannot be a moped.


- **Bicycles**: They are not mentioned in the fragments, but generally do not have engines that allow them to reach speeds over 45 km/h.

Therefore, a two-wheeled vehicle that can go faster than 45 km/h is classified as a **motorcycle**.