Aftermarket rear master cylinder mounting for disk brake

Kyleshep49

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Hello i am new here, currently building a 81 xs650 into a street tracker. I race flat track sometimes in Miami and i got this bike a while ago. I’m trying to build a racer mainly but still have it street legal. The old owner had started the process of rear disk conversion with the 19 front mag front and rear but i still need to figure out how to mount the rear master cylinder. I’ve been searching these forums non stop and google for pics or info, but it seems like everyone just uses the stock mc and whatnot. I have two different aftermarket ones. Brembo and some Amazon ordered one. Can people post some pics of some non traditional mounting jobs so i can get some ideas. Thank you!
 

DogBunny

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This is a hard tail with forward controls, so It's a lot different from what you're going to do, but maybe the process I used will help you. I acquired the bike as a project that needed all the details, but the heavy lifting had already been done. I bought the absolute cheapest master cylinder out there. Frame was already welded and powdercoated so I needed to attach a mounting bracket for the M/C without welding. Bolted an angle iron to the frame -- green arrows at the bottom of the pic, those are the bolt heads.

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The forward controls push toward the back, so I didn't need the stock rear brake pedal pivot. I just made a super rigid and straight and secure link to the push rod on the M/C.

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Normally you'd attach the M/C reservoir to the frame somewhere, but I couldn't see a place to put it that would look good, so I just attached the reservoir directly to the M/C with a very rigid tube. So, the reservoir is just sort of hanging there. I'd probably ditch the reservoir and just use a short pipe elbow as a reservoir next time.
Anyways, it all works just fine. My suggestion would be to buy a M/C, get it in your hands, and just play around with different positions and linkage ideas.
 

hovel

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My suggestion would be to buy a M/C, get it in your hands, and just play around with different positions and linkage ideas.
Excellent, excellent advice. Even if you shit-can what you have in your hands, the design process is working.
Now, on to the bike: not exactly my style, but I believe I could hunker down and just get lost in the detail for an hour or so. The execution is impeccable.
 
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