No, the KTM RC390 is not the fastest bike available. While the KTM RC390 is a sporty motorcycle with impressive performance for its class, there are numerous motorcycles with higher top speeds and greater overall performance capabilities.
The top speed of a motorcycle depends on various factors such as engine power, aerodynamics, weight, and gearing. In the case of the KTM RC390, it has a top speed of around 105 mph (169 km/h), which is respectable for a small-displacement sport bike.
These motorcycles often feature larger engines, advanced aerodynamics, and other performance enhancements, allowing them to achieve higher top speeds.