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zx10 brakes

Discussion in 'Modifications and Projects' started by csgup1, Oct 17, 2008.

  1. hey all

    ive got an 04 zx10 and im not the happiest with the brakes. the lever is extremly spongy and can touch the bar with no real effort.

    having done some research people say that a new master cylinder or calipers of a zx14 would be the best bet .

    would braided brake lines make much of a difference.
    if so where would be the best place to get them from??

  2. Your ZX10 is now 4 years old which means the standard rubber hoses have gone beyond their O.E.M. use-by date.

    Bear in mind that your DOT 4 brake fluid is only good for about 12 months as well.

    You may only need to flush and replace the brake fluid but fitting braided Stainless hoses will offer a huge improvement in feel and performance.
  3. Maybe its been run dry in the past, try bleeding the brakes and flushing thru the old fluid before you start replacing parts.
  4. I ride a 1998 Blade and my original hoses have no problems whatsoever. I would first of all flush and bleed your brake fluid. I would also check your brake pads, see how much meat is left. Trust me your Zx10 comes with ample brakes as standard, you don't need to upgrade to fix your problem.
  5. thanks for the reply guys

    the brakes were bled recently and the pads still have enough meat on them .

    i tihnk braded lines would be the go. any ideas where to get the best deals?
  6. Any performance brake shop can do them. Like Race Brakes Sydney in Wetherhill Park.

    Though just check that they are the ADR Compliant braided lines or else they aren't road legal... Race Brakes Sydney make Goodridge ADR Compliant lines. (Goodridge are about the best of the braided line manufacturers)
  7. i know you said you had the breaks bled but have you replaced the break fluid. meaning flushing it all out. sounds like the fluid has absorbed water (which is what will happen over time), just my 2c
  8. yea the fluid was replaced. replaced the calipers the otherday with zx14 ones. got them at a steal and the brakes are bloody awesome!!!!! recpmmend them to every zx10 owner.

    would like to change the mc from the 14 to a brembo 20 or 18 .

    one finger stoppies !!!
  9. Errr..... Increasing the M/C diameter will actually increase the force you need to apply at the lever.

    Having said that, I doubt you current M/C is a 14mm piston.
  10. hmm i would have thought the more the diameter is the more fluid you push out and leverage you have . oh well.

    the current one says 14 on the MC . could that be something else??
  11. Spot on. Larger bore displaces more fluid for less lever effort.

    The "14" cast onto the body denotes 14mm bore diameter.
  12. Wrong.
  13. Really?

    A 450MX bike has an 11mm bore ( 11 is cast into the body ) feeding 2 small pistons.
    My MV Agusta has a 5/8 bore (again cast into the body) feeding 12 pistons.
    The radials on our Ducati Race bike has a 19mm bore. Not too much effort required to brake there.

    Please explain the hydraulic (dis)advantage to me because I've obviously missed something in the last 25 years in the trade.
  14. [​IMG]
    Call piston 1 your M/C, piston 2 the combined area of your caliper pistons. Without changing your caliper, increasing the bore of your M/C increases the force (F1 in pic) required to have the same equivalent force (F2) applied to the brake pads as before. The piston travel at the M/C is reduced, the force required is increased.

    The other factor, is the leverage gained by changing pivot points for a given piston size. On M/C's like a traditional brembo radial, the pivot point might be 16, 18 20mm etc past the piston, changing both the travel and the lever pressure required.

    Comparing bikes like you have, says nothing to counter the point that increasing M/C bore (without changing anything else) will increase the effort required at the lever. A 20mm master with dual 4 piston calipers may indeed require less effort at the lever than an 11mm master on a single 2 pot dirt bike caliper, and the reverse could be true also. Pointless.

    Sorry, but it's scary that you're 25 years in as a bike tech (I'm presuming).
  15. Well it's certainly a delightful (if slightly ambiguous) diagram. Sorry I'm not up on cutting and pasting shit from all over the internet to try to prove my point of view. Sadly, I only have real world experience.

    I've converted dozens of bikes from single to twin disc. Hence, A2 becomes larger than A1. The master cylinder bore ALWAYS has to be increased otherwise the lever comes in to the bar and the brakes dont work. Thus, A1 must be increased to compensate.

    I machined our Brembo master cylinder from 17mm to 19mm myself. The brake effort at the lever was lessened and the overall brake performance increased. A1 was increased. Again. Nothing to do with "lever ratios" or "pivot points" which are unchanged.

    Finally, don't apologize or be frightened. I'm doing quite OK for myself. Thanks.
  16. Of course you have to increase M/C bore size when increasing the size of the caliper. Don't mix up lever travel for force required at the lever.

    Listen, forget about it. I tried to explain the most basic of hydraulic principles, if you choose not to believe a basic scientific principle all power to you. You will sound like a moron to any of your customers or colleagues that have half a clue.

    "Hey MSC, I don't want to have to use 4 fingers and it's a bit wooden"

    "No worries mate, a larger M/C and you'll be right"


    I'm out, but for anyone that cares I will cut and paste this time so you don't have to believe just me (I don't have 25 years experience after all). :roll:

    Wiki: A larger diameter master cylinder delivers more hydraulic fluid, yet requires more brake lever force and less brake lever stroke to achieve a given deceleration. A smaller diameter master cylinder has the opposite effect.