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  1. #1
    Lover, not a fighter...
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    Should I let my friend put DOT 5.1 in his Strokers?

    Like me, my best friend Allen spends way too much time online reading stuff. He has Stroker Carbons and is convinced by an article he read online that he will get better modulation by replacing the DOT 4 with 5.1.

    I told him he might want to get smaller rotors or try different pads first, eh? He has V7s and they're on his FS trail bike. From what I've read, Hayes says only DOT 3 or 4 is safe or the seals will go. Is this true? What's the chemical difference? Also, what's the best fluid to use? I have BB7s and older Shimanos on my bikes, so I have no idea.

  2. #2
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    changing brake fluid isn't gonna get you better modulation. different pads will change modulation and power

  3. #3
    TNC
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    3, 4, and 5.1 are compatible with each other. If you want some real engineering rundown on the differences, go to some of the dirt motor sites like Thumpertalk and such. Good info there. The boiling point goes up with the higher number value. The ability to resist moisture absorption also goes up with the number value...hydroscopic rating I think. The brake fluid you have to avoid in many DOT based hydros is DOT 5. It's confusing because it's obviously labeled close to DOT 5.1.

    As to affecting modulation, as vk stated there should be no discernable difference in a bicycle hydro. I guess some modulation performance could/would occur on some DH rig with a WC level rider on board in some goshawfully steep DH conditions between DOT 3 and 5.1, but do those guys actually use their brakes?...LOL!

    If I recall, DOT 3 has a general boiling point around 280 degrees or so, and 5.1 boils at about 350, and DOT 4 at about 310. DOT 4 is probably all that mere mortals need, and it's available at any auto parts store.

  4. #4
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    Directly from Hayes:

    ....The answer is simple:

    We can not recommend any fluid that we have not specifically tested with. Reason being that we canít say that our seals wonít react adversely overtime to the DOT5.1 due to the additional additives that are found in it, and Iím reasonably certain you could see why that could be an issue!

  5. #5
    TNC
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    Quote Originally Posted by Renovatio
    Directly from Hayes:
    Yeah...someone also said artificial sweetners were safe, and Anna Nicole married for love.

  6. #6
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    Well manufacturers will often give you that to avoid liability issues and if they sell the brake fluid themselves, why warranty the use of some other guy's fluid?

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