They tried to patent it but I believe they were not successful. And it's not the loud sound, it was the unique sounds from the firing order that's unique to their v-twins. New Harley's sound like sewing machines, but most people change their exhausts.
Their unique sound is what helps sells their bikes so it's why they go out of their way to make sure their motorcycles have it.
tina_the_fat_llama t1_iu16ngp wrote
Reply to comment by From_Deep_Space in Harley-Davidson Model 1, the first motorcycle ever produced by the motorcycle company. by swizchaksih74
They tried to patent it but I believe they were not successful. And it's not the loud sound, it was the unique sounds from the firing order that's unique to their v-twins. New Harley's sound like sewing machines, but most people change their exhausts.
Their unique sound is what helps sells their bikes so it's why they go out of their way to make sure their motorcycles have it.