MANDELLO DEL LARIO, Italy — A motorcycle factory sits on the edge of Lake Como in a little town that proudly proclaims itself “La Citta Del La Moto Guzzi” — the city of Moto Guzzi.

On paper, based solely on numbers, it's kind of hard to make a case for Moto Guzzi . Its bikes are never the most powerful or sophisticated in their class, neither are they the cheapest or most ...