The Harley exhaust note is mostly a product of the configuration of the engine. The V twin engine is indexed from one cylinder to the other in an awkward position. Most engine designs try to have one cylinder firing while it's "twin" cylinder is starting the exhaust cycle to maintain some semblance of balance. The degrees of separation Harley chose creates the loved/hated Harley imbalance/vibration, and also gives that unique (no one else is dumb enough to intentionally build an imbalanced engine) P-O-T-A-T-E-O, P-O-T-A-T-E-O exhaust note. It is almost like a heart-beat (lub-dub-space-lub-dub-space). The V Rod is the exception.
Is that why most (older) Harley riders have double vision and no teeth - they've been affected by the terrible imbalance of the engine?

