If there is one rant we hear more than any other these days, it is about the obnoxious noise level emitted by off-road, four-stroke bikes. One of those rants goes a little bit like this. Manufacturers are shooting themselves in the foot when they refuse to trade loud, four-stroke exhausts for a horsepower or two. Why? Because riding areas are being shut down, and will be shut down, due to excessive noise. Fewer riding areas means fewer bike sales . . . gunshot wound to the foot of off-road manufacturers.
KTM is apparently doing something about this. Last year, their line of SuperMoto bikes, the 450 SMR and 525 SMR models, ran the same mufflers as their motocross machines (termed “SX” models). These mufflers are pretty noisy, although slightly quieter than most of the competition.
For 2005, the 450 SMR and 525 SMR models received new mufflers derived from KTM’s European EXC models. These mufflers are dramatically quieter than your typical motocross muffler, and emit a claimed 93 decibels maximum. To give you a frame of reference, some of the off-the-shelf, four-stroke motocross bikes sold here in the United States are in the 100 decibel range. If that doesn’t sound like a big difference, remember that sound level increases on the decibel scale are non-linear. In other words, two or three decibels makes a huge difference, and six to eight decibels makes a massive difference in perceived sound level.
Our associate editor, Alex Edge, had a chance to ride a 525 SMR at a KTM press event on Tuesday, and reports the bikes are pretty darn quiet, particularly, when compared with a typical motocross bike. Kudos to KTM. We hope other manufacturers follow suit.
