Bought too large of a clutch master, would a larger line help reduce lever effort?

Discussion in 'Tech' started by Ungarisch, Jul 9, 2019.

  1. Ungarisch

    Ungarisch Member

    Earlier this year I upgraded my stock Nissin radial 19mm brake master to the Brembo 19RCS 19mm radial and it works perfect.

    Last month, to match my shiny new Brembo brake master, I bough the Brembo 16RCS 16mm radial clutch master cylinder to replace my Magura axial master. I did not realize that my Magura was a 10.5mm piston dia., and the new Brembo is a much larger 16mm dia., and now my clutch lever is much harder to pull, though with the added benefit of a much longer "cable pull" / throw, making neutral super easy to find. With the Magura the clutch activation arm moved 8mm, while with the new Brembo the trow is now 13mm, much more than what is needed for clutch disengagement. Unfortunately 16mm master is the smallest dia. clutch master that Brembo sells in the radial type, so I cannot get a smaller one.

    One saving grace though that I think could help me is that my current clutch hydraulic line is the small 5.25mm OD (2mm ID) bicycle type of line, while a standard motorcycle stainless brake lines is 7.5mm OD (3.5mm ID), and I am HOPING that maybe my fluid displacement logic is correct and that if I change out my current tiny line with a standard large diameter braided line which has a 50% larger line diameter, it would yield the same result as having a larger slave or smaller master.

    I've just been back and forth whether this logic makes any sense and I'm hoping someone more educated on fluid dynamics can chime in and confirm this theory before I waste any more money. Much Appreciated!!!
  2. fastfreddie

    fastfreddie Well-Known Member

    Line size is irrelevant.

    Consider that the clutch engagement could be a little easier to modulate when launching with that "cable pull", too.
    pscook likes this.
  3. Spitz

    Spitz Well-Known Member

    The system is just going to hold more fluid is all.
    pscook likes this.
  4. RM Racing

    RM Racing Tool user

    Put the Magura back on. Why do the parts have to match? Function over form.

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