The rumble is caused by the V Twin’s horrible original design. It’s arguably the most poorly balanced piston engine ever created. More on that later.
BMW’s flat twin design is infinitely smoother as it’s piston motion occurs on a single axis. It’s disadvantage is that the protruding cylinder heads create road clearance problems for those of us that are man enough to properly stuff it into corners.
Honda experimented with smoother V Four designs but proved difficult to cool uniformly.
The most naturally balanced engines are wide angle V12s as the cycle of some cylinders cancel the vibration of others. But back to motorcycles…
The V Twin problem:
Imagine looking at V Twin equipped motorcycle from the side. Now visualize a clock in front of the motor’s side. Combustion occurs only at 11 and then 1 O’clock.
The result is the grating pause THUMP pause THUMP pause pause pause pause pause pause pause pause pause THUMP pause THUMP pause pause, etc. racket.
The Harley Davidson Evolution engine attempted to minimize this issue by altering the points on the crank where the connecting rods attach.
So when some leatherhead thinks he’s all macho setting off every car alarm on my street he has instead invested in already bad outdated technology.
Sad.
He could have instead mounted a proper modern sportbike that screams effortlessly to +13,000 RPM
REGARDING ALL THE PENIS COMPENSATION CRAP ITT:
People that make such unfounded observations are demonstrating classic fear of that which they do not understand. You’re a ‘phobe, pure and simple, like any other kind. Perhaps it’s best if you don’t discuss things you cannot comprehend.
Yes, my Integra is somewhat loud but not for it’s own sake. The open intake, free flow exhaust and catalytic converter delete (sue me) makes for a satisfying sound but more importantly increases the car’s performance. This results in FUN, not fretting about the bulge in my trousers.
Extra credit: If one dissects a Boxer dog one finds that it is powered by a flat twin engine.