Not at all true, unless you add an illegal straight through or race pipe. Or remove the baffles. Motorcycles are comparatively loud, especially big V twins, be

Not at all true, unless you add an illegal straight through or race pipe. Or remove the baffles. Motorcycles are comparatively loud, especially big V twins, because a) a surprising percentage is intake noise - there's a huge intake pulse from a 1200cc V b) the engine is open rather than behind a closed bonnet with noise absorption c) they tend to rev much higher than equivalent car engines (not Harleys) Passing the legislated noise tests (specified engine revs etc), bikes are often quieter than a car. With some bikes now too quiet for comfort around pedestrians in town. Harleys somehow are always obnoxiously loud - My guess is probably mostly from intake pulses given current EU noise regs.