200mm Rotor Users

2

Comments

  • mrfmilo
    mrfmilo Posts: 2,250
    Bleeding doesn't prevent boiling, or prevent them from being utter shite.

    Old (especially DOT 4) water contaminated bleed is gonna boil faster than a good fresh bleed.
  • Anonymous
    Anonymous Posts: 79,667
    And if the brakes are functionally fine, how would water get into them, exactly?
  • mrfmilo
    mrfmilo Posts: 2,250
    DOT fluid is hygroscopic

    Im not 'defending' Juicys, as they are sh*t :lol: Just saying with a good setup they're not as bad as people make out i've found.
  • sheepsteeth
    sheepsteeth Posts: 17,418
    ive used most versins of juicys and still have sevens on my edison, they work fine for me, maybe i have been lucky.

    i use big discs and sintered pads but to be fair, i ride very slowly.
  • Anonymous
    Anonymous Posts: 79,667
    mrfmilo wrote:
    DOT fluid is hygroscopic

    Im not 'defending' Juicys, as they are sh*t :lol: Just saying with a good setup they're not as bad as people make out i've found.
    Nice. So are you suggesting that I'm a mechanical buffoon?
  • Northwind
    Northwind Posts: 14,675
    So are you suggesting that I'm a mechanical buffoon?

    I think you're an organic buffoon. But there's definately some evidence that you're some sort of evil robot to be fair, so I'm keeping an open mind.
    Uncompromising extremist
  • Anonymous
    Anonymous Posts: 79,667
    :lol:
  • nicklouse
    nicklouse Posts: 50,675
    mrfmilo wrote:
    DOT fluid is hygroscopic
    .

    so? that is a good thing.

    water in a Mineral based system is a bad thing as it just sits there at the lowest point waiting.

    water in a braking system is not actually a bad thing. Just dont get it too hot or too cold.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mrfmilo
    mrfmilo Posts: 2,250
    nicklouse wrote:
    mrfmilo wrote:
    DOT fluid is hygroscopic
    .

    so? that is a good thing.

    water in a Mineral based system is a bad thing as it just sits there at the lowest point waiting.

    water in a braking system is not actually a bad thing. Just dont get it too hot or too cold.

    That is the situation I was describing, as yeehaa said his overheated.

    And it surely can't be a good thing?
  • nicklouse
    nicklouse Posts: 50,675
    DOT fluid is designed to work with some water in it. It also still has a higher boil point than Mineral.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mrfmilo
    mrfmilo Posts: 2,250
    nicklouse wrote:
    DOT fluid is designed to work with some water in it. It also still has a higher boil point than Mineral.

    Must be a limit to how much it works well with though?

    I've been told for example not to used DOT fluid that's been stored for a long time as it's absorbed water.
  • Anonymous
    Anonymous Posts: 79,667
    If its absorbing excess water, whilst sitting in your (mountain bike) brake system, then your seals are gone.
  • mrfmilo
    mrfmilo Posts: 2,250
    Fair point.
  • schmako
    schmako Posts: 1,982
    I do like the 203 rotors, they stop on super steep stuff. Whereas the 160's definitely don't feel as safe on the steep stuff. This could also be due to the fact that the 160's are LX's and the 203's are M4's.

    So yeah, kinda pointless post really.
  • NatoED
    NatoED Posts: 480
    dot fluid absorbs air too and thats the biggest problem with stored fluid .
  • Anonymous
    Anonymous Posts: 79,667
    I thought it sucked in the moisture from the air.
  • I'm running 160 rotors on M445 calipers, if I upgraded to 180 or 203 rotors would it place more 'stress' on the calipers in terms of heating/boiling the fluid?

    Also on heavy braking the 160's can flex the 29" wheels a bit, I'm guessing this would be exaggerated with larger rotors?
    2011 Cannondale Trail SL 29er HERE
  • supersonic
    supersonic Posts: 82,708
    The larger area of the rotor allows more heat to dissipate - caliper temps are reduced.

    Slightly less force is put through the fork dropouts than smaller rotors, but more through the mounts - check what your fork can handle: this is the important bit.

    Larger rotors make no difference to wheel flex, providing you can lock wheels up on both size rotors.
  • Thank you :wink:
    supersonic wrote:
    Slightly less force is put through the fork dropouts than smaller rotors, but more through the mounts - check what your fork can handle: this is the important bit.

    Whereabouts would one find that?
    2011 Cannondale Trail SL 29er HERE
  • supersonic
    supersonic Posts: 82,708
    In the blurb and warranty usually.
  • Northwind
    Northwind Posts: 14,675
    If its absorbing excess water, whilst sitting in your (mountain bike) brake system, then your seals are gone.

    The other thing is, pushbike bleeds tend not to last all that long- we replace brakes, bikes, rebuild stuff onto different frames, damage hoses, etc etc. So it's not like, frinstance, motorbikes where cretins happilly leave the same fluid in the bike for a decade then go and do a trackday.
    Uncompromising extremist
  • Anonymous
    Anonymous Posts: 79,667
    What?
  • Northwind
    Northwind Posts: 14,675
    What?
    Uncompromising extremist
  • Anonymous
    Anonymous Posts: 79,667
    Huh?
  • ilovedirt
    ilovedirt Posts: 5,798
    edited August 2011
    Just to add my 0.02 worth, I've recently upgraded from some 185/160mm juicy 3's to some 203/203mm formula megas on my patriot, and the formulas are just as easy to modulate, if not more so, and have bags more power. If you can't modulate your brakes on 203mm rotors without locking the wheels up, you're being too ham-fisted, or your brakes are shite (in my opinion/experience).
    Production Privee Shan

    B'Twin Triban 5
  • Northwind
    Northwind Posts: 14,675
    Buh?
    Uncompromising extremist
  • Anonymous
    Anonymous Posts: 79,667
    ilovedirt, there's a thing called personal preference. Different people like different things. Shocking, I know.
  • ilovedirt
    ilovedirt Posts: 5,798
    ilovedirt, there's a thing called personal preference. Different people like different things. Shocking, I know.
    That's true, however being able to modulate a set of brakes properly has little to do with that. Of course they're going to lock up if you just pull on the levers like a monkey. Obviously some will be worse than others, but "big brakes are hard to modulate" isn't exactly a hard and fast rule.
    Production Privee Shan

    B'Twin Triban 5
  • Anonymous
    Anonymous Posts: 79,667
    But people's preferences over lever feel differ.
  • ilovedirt
    ilovedirt Posts: 5,798
    True, though why you would want on/off brakes with no modulation is beyond me...
    Production Privee Shan

    B'Twin Triban 5