Two Brothers S1R Slip-On Exhaust KTM RC390 2015-2017
Two Brothers S1R Slip-On Exhaust
The Two Brothers S1R Slip-On Exhaust represents a step into the future for TBR. The S1R exhaust features a carbon fiber sleeve highlighted by a natural aluminum outlet and stamped, spring-mounted inlet for the ultimate durability. Like most TBR mufflers, the end cap of the S1R exhaust is constructed of magnesium and features a non-stick teflon coating. However, that is where the similarities end.
The aggressive design of the end cap is reminiscent of the modern jet engine making this exhaust move at mach 1 speeds while standing still. The carbon fiber sleeve of the S1R exhaust system is made of a 33 million modulus rated carbon fiber that is impregnated with high temperature resin, under very tight tolerances. Thirty-three million modulus rated carbon fiber can be considered the Goldilocks of carbon fiber , it has strong structural properties without being overly stiff and brittle, making it just right.
The sound produced by the S1R is deep and throaty thanks to its spiral-wound perforated core technology. The rubber-lined, natural finished aluminum muffler clamps feature an aggressive angular design and cutouts to reduce weight. The mid-pipe is constructed from .035” thick 304 stainless steel. After a few heat cycles the 304 steel turns a golden amber color, the hallmark of quality stainless. Of course an exhaust can't be all show and no go, that is why the S1R exhaust is track-tested and dyno-tuned to offer the best performance package.
- Fully-serviceable in the event of damage, routine maintenance or the occasional repack
- Aerospace high-temp carbon fiber
- Stamped spring-fit inlet
- Optional P1 and PX1 sound inserts available (sold separately)
- Optional anodized bolts kits available (sold separately)
- Made in USA