The phrase "black leather motorcycle" refers to a type of motorbike that is made with black leather material for its body and other components. This means that the bike has a sleek, stylish look and is often associated with rebellion or freedom. The use of black leather also adds an element of toughness and durability to the motorcycle, making it suitable for long rides and adventurous journeys. Overall, the phrase "black leather motorcycle" describes a powerful and eye-catching vehicle that is popular among bikers and enthusiasts alike.