The distinction between an ATV (All-Terrain Vehicle) and a motorcycle is not solely based on speed. It primarily depends on the vehicle's design, features, and intended use. ATVs are generally defined as vehicles designed for off-road use, with features such as low-pressure tires, a straddle seating position, and handlebar steering. Motorcycles, on the other hand, are two-wheeled vehicles typically designed for on-road use.
The speed at which an ATV becomes a motorcycle is not a universally defined threshold. Different jurisdictions may have varying regulations and definitions regarding vehicle classifications. In many regions, including the United States, there isn't a specific speed at which an ATV becomes a motorcycle. Instead, the classification is typically based on factors such as the number of wheels, engine displacement, and intended use.
It's important to consult the specific laws and regulations of your country or region to determine the classification criteria for ATVs and motorcycles in your area. These regulations can provide clarity on the legal distinctions and requirements for different types of vehicles.