Brembo Master Cylinder?

Discussion in 'Parallel Universe' started by Gangplank, Jul 14, 2011.

  1. Gangplank

    Gangplank Advenchaintourer

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    I'm thiking of going to a brembo master.

    Does anyone know the size of the BMW master cylider? I'm not sure yet which Brembo master would be the right one. They make a number of different options:

    16x18
    16x20
    19x18
    19x20

    The first # is the bore size of the master the second # is the axis or pull distance of the lever. 16's are typically for bikes with a single disc vs.
    19s which are for bikes with a dual disc but I'd rather know for sure.

    The axis or pull distance is personal preference "as that number increases it decreases the sensitivity and increases brake power." Lower numbers (x18) are said to give better feel to the brakes whereas bigger number (x20) more power to the pull. More info here: http://www.oppracing.com/pages/articles_brembo_master_cylinders/

    Anyone know the volume or bore size of the BMW stock master cylinder? Is it a 16 or 19mm?

    Brembo makes some nifty new models like the 16RCS and 19RCS that are adjsutable: 16RCS will be a 16x18 or 16x20. The 19RCS can be a 19x18 or 19x20. Lets you adjust the feel.
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  2. LukasM

    LukasM Long timer

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    Caliper is not caliper. Sportbikes generally use 4 pistons, we have 2. Size on these is also different, even some of the 2 piston Brembo look-a-likes are different. AFAIK the GS uses 30 and 32mm pistons.

    16mm sounds about right, 19mm will be rock hard with horrible feel.
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  3. Gangplank

    Gangplank Advenchaintourer

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    yep that is what I was thinking. A 16x18. Wondering what the actual size is tho before spending the $$. Don't want to pay just to find out I have a rock hard lever and wooden feel.

    Idea is to improve lever action and feel.

    That said with a 2 pot caliper it still might be overkill at 16x18. They make smaller sizes and even getting a used one from an older duc might get better action and elimiante the urine bobble thing.

    Need to know the size. Help if I knew the brand of the thing.
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  4. takkyhide

    takkyhide n00b

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    Bring this back to live.

    Anyone done a 19RCS or 16RCS (which ever is compatible) on their F8? How's the feel and any impact to ABS?
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  5. NCD

    NCD Dirty Hairy

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    There may be an easier way to do this now. The 2013s have the Res Cup right on the lever now. No rubber hose. Just at a glance, it looks like you could remove the old bobble, hose, and adapter on the lever and replace it with the 13 Res Cup assy. Looks like it will work.

    If you look at the underside of your lever, there are 2 screws coming from underneath that attach an adapter for the bobble hose. Seems like the adapter could be swapped for the new integrated reservoir. I haven't had a chance to investigate further......

    Of course, this is just cosmetic.
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  6. Gangplank

    Gangplank Advenchaintourer

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    Either will be compatible. It just depends on how much stopping power you want. I have a 19 RCS on my gsxr 750 track bike. It's like magic on the track. Everyone who rides the trackbike wants one. Just need to find the specs on the BMW to see what size the piston is or just try it. Given the power of my gsxr at 130 HP & how hard it brakes I might suggest the 16 RCS would be adequate on the f800
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  7. LukasM

    LukasM Long timer

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    Not sure I follow your reasoning. The horses of your GSXR and it's stopping power have nothing to do with the sizing of the MC. That solely depends on how many brake pistons you have to move, how big they are, and whether you prefer the feel of a hard pressure point at the lever or a more progressive ones. Both will give exactly the same stopping power as long as you are moving enough fluid (too small of a piston and you'll run out of lever travel) and pulling the lever hard enough.

    For the F800GS a 16mm piston is not only "adequate", it will feel a lot better than 19mm. Stock is 15mm I think.
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  8. Gangplank

    Gangplank Advenchaintourer

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    19 = more fluid pushed = more force
    16 = less fluid and less force applied to the brake.

    You do know Brembo makes an adjustable one right? It can be a 20 or 18 with the turn of a screw. Difference is pretty noticeable.
    #8