Bmw R1150rs Custom Exhaust System

The BMW R1150RS like most all late model BMW motorcycles, has a catalytic converter mounted right under the transmission. The extra heat from the “cat” can’t be good for the oil in the transmission. And the total exhaust system on this bike must weigh 25 pounds! It need to be farkled!


I ordered a couple of 2″, 45 degree exhaust pipes from JC Whitney.
Item number 812935 for $12.99 each. My local sport bike motorcycle shop was cleaning out the back room and I bought a “Scorpion” stainless steel, oval muffler meant for a 1999 Honda CBR900RR  ($150). I chose this muffler as it used bolt on flange rather than a preset slip on pipe. I figured I could manipulate the attachment angle better with this mounting system. I also bought a couple of 2″ muffler clamps at the local auto parts store.


I removed the old system and two of the pipes were joined together to cross over from one side of the bike to the other.

On the exhaust side, the pipe was cut to length and a flange I fabricated out of a piece of 3/16″ sheet steel was welded on at the proper angle.


I was able to use the factory mounting point with the supplied muffler band.


On the other side I drilled and tapped a hole for the O2 sensor.


Upon completion, it looks a bit nicer and it sits tighter to the bike so when I fabricate mounts for my GIVI kuggage, the total bike will be narrower.





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4 comments on “Bmw R1150rs Custom Exhaust System”

  1. Mark Reply

    Hi. R1150R Rockster owner here, contemplating exhaust change that would include the R1150RS/RT header, with customer section like that you fabricated to connect header to muffler.

    Is the R1150RS header outlet (pre-cat) 2″ as per your 45-degree pieces?

  2. John rossiter Reply


    I have the same bike as pictured with all the stock hard cases. Was wanting to go with an after market exhaust to improve power and reduce weight. Do you have any suggestions on which system you might suggest?

    • Roy Bertalotto

      At this time I’m not up to date on what is available or recommended by the BMW crowd. I’d suggest asking at one of the various forums. Thanks!

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