The top speed of a Harley-Davidson motorcycle without modifications can vary depending on the model and engine size. However, it is important to note that the top speed achieved by a motorcycle is influenced by various factors such as aerodynamics, rider weight, road conditions, and more.
On average, most Harley-Davidson motorcycles can reach a top speed of around 110 to 130 miles per hour (177 to 209 kilometers per hour) on flat ground without modifications. However, some high-performance models, such as the Harley-Davidson V-Rod, can achieve higher speeds, potentially exceeding 140 miles per hour (225 kilometers per hour).
It's worth mentioning that riding at extremely high speeds can be dangerous and is generally not recommended for public roads due to safety concerns. Always prioritize your safety and adhere to local traffic laws and speed limits.