vented caliper pistons

Discussion in 'Mods, Upgrades, Accessories and Products' started by Cookster, Aug 24, 2021.

  1. Cookster

    Cookster Active Member

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    hi guys any one using brake tech vented caliper pistons on there bike?? after some info to see if they make a difference.

    cheers
     
    #1 Cookster, Aug 24, 2021
    Last edited: Aug 24, 2021
  2. dern

    dern Well-Known Member

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    Take a look at your calipers and if the pads are worn enough to expose the holes that are in the vented pistons then you need new pads and that's probably your problem.

    Looks like a gimmick to me and I'd be surprised if there's anywhere near enough airflow for them to make any difference at all.

    To answer your question though, no, not using them.
     
  3. Cookster

    Cookster Active Member

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    cheers mate that does make sence to be fair, i only ask as ive been offered a set of hpk calipers for the blade, but there quite expensive just seeing it its worth modding standard calipers or go the hpk route.
     
  4. dern

    dern Well-Known Member

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    What's the problem you are trying to solve? I think a lot of bikes are running standard kit on track, including myself, and it largely works well.
     
  5. Cookster

    Cookster Active Member

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    the problem with the brakes is an awfull lot of travel at the lever, ive changed the pads to sc and changed brake fluid, i have got an rcs going on and a set of hpk discs but thought seeing is its apart again is it worth modding either standard calipers or change the calipers completley??
     
  6. dern

    dern Well-Known Member

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    I wouldn't do that, I'd see if the master cylinder fixes the issue as that seems to be quite a common thing on these bikes. Have you changed the hoses, I assume that you have. Work on the calipers will only mean refilling the fluid so it's not too big a deal to do that later.
     
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  7. warren smart

    warren smart Active Member

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    The nissin calipers I’ve fitted on my rsv come with vented pistons and brembo make numerous calipers with vented pistons as well.
     
  8. dern

    dern Well-Known Member

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    If they make a difference then I happily stand corrected. If heat is an issue beyond what can be handled by a standard system I don't understand why they don't put them in the airflow and stick a heat sink to them. Seems like a really odd solution. Anyway, everyday is a school day :)
     
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  9. warren smart

    warren smart Active Member

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    You can buy pad back plates with a heat sink on them that sits out in the airflow, I haven’t seen any used though.
     
  10. dern

    dern Well-Known Member

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    That makes more sense to me.
     
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  11. Jez

    Jez Senior Member

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    putting anything the between the piston and pad has the chance of increasing sponginess
     
  12. warren smart

    warren smart Active Member

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    The oe tokico’s on mine with an rcs master and braided lines gave a very firm lever, I would try re bleeding and tying the lever back overnight.
     
  13. Cookster

    Cookster Active Member

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    they have been bled twice now and still shit, ok it stops but not great, il try rsc first and go from there.
     
  14. warren smart

    warren smart Active Member

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    A friend asked me to put brembo corsa corta masters on his early 916 with braided lines, the feeling at the lever went from ok to very firm quickly with axial calipers.
     
  15. Cookster

    Cookster Active Member

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    thats good news mate.
     
    #16 Cookster, Aug 26, 2021
    Last edited: Aug 26, 2021
  16. Slick

    Slick Elite Member

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    Theoretically travel is the controlled by the hydraulic ratio between pistons and master and the lever pivot length.
    But in reality alot is due to pistons retracting due the seals sticking and air in the system

    Personally I have RCS19s/OEM callipers with stainless steel pistons polished to a mirror finish, with the lubed with brake fluid and pins with a tiny amount of anti corrosion. Suffice to say the travel is consistent and feel is hard without being dead - and I have an ABS*

    * bit of a lie the ABS is deactivated!
     
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  17. Black & White

    Black & White Well-Known Member

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    Have you bedded the new pads into the discs? You will get excess travel/sponginess as the pad material distorts into the existing grooves on the discs.
    If you have a spare reservoir cap, it could be worth buying a Gunsons eezibleed (or similar [Bluespot?]) & drilling a suitable hole in the reservoir cap to suit the pressure bleeder.
     
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  18. Cookster

    Cookster Active Member

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    well guys the new master cylinder had done the trick, brakes are really good now, also got hpk discs and sc brembo pads in there now
     
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  19. kirk holmes

    kirk holmes Member

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    What master cyclinder did you go for?
     

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