Exhaust systems for classics
Factory exhaust systems were never constructed for eternity. They must ensure optimum power development and maximum noise reduction during their lifetime. And that the interpretation of that value has been interpreted differently over the years? So be it.
In the meantime, such an exhaust system is exposed to weather and wind, to heat and cooling, to vibrations and to chemical attack by acidic condensation after short journeys. And we are not even talking about dents and scrapes.
New original exhaust systems had their price. The supply market dared to do so. In the time of the European 1 and 2 cylinders, making an exhaust system was a fairly simple job for someone with a roller and a welding machine. That kind of simple replacement exhausts was therefore offered very early and for good prices. And whether an 350 cc BSA made a little more or less noise and whether he had received a horsepower or lost one? Pfah. Nice and important.
The Japanese made it difficult
Everything changed with the arrival of the Japanese four-cylinder. Their exhaust systems were really designed for optimum gas flow and noise reduction. And the outside of the dampers was formed by pressed and welded shell parts containing all sorts of dents, naps and holes to make room for brakes, center stands and bump rubbers. The entire design and implementation was based on mass production. And that is why the construction of expensive press molds was just the right approach. Only: the average blacksmith really couldn't make four in four sets of Honda CB750 OHC dampers in an afternoon. And replaced by original? That was expensive. Very expensive. Fortunately at that time there were almost no problems with engine noise and the suppliers started to make four-in-one systems en masse. They were cheaper and considerably lighter too. And that some specimens were very loud? We thought that was beautiful!
Cost (an) ability
In a comparison test in Das Motorrad, the Germans looked at a dozen four-in-one systems for the Kawa Z900. The best system delivered almost as much power as the original set of pipes. The worst rated system lost a herd of 14 horses.
In the meantime, those difficult Japanese bicycles are well worth the restoration. And those exhaust systems? The NOS stock has since dried up. But there are a few investors globally who - of course in China - have had serious press molds made again. That is why there are now new exhaust silencers, real replicas including the correct numbers, for at least Honda CB450 K1s, CB750 OHCs, Kawasaki MachIII's 900 and – from the Netherlands! - Suzuki T500s
And that such a set of beautiful things can just be in the neighborhood of the two mille of rock hard euros? Well: better expensive than not for sale.
