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Thread: Brake Fad

  1. #1
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    Brake Fad

    Alright, I am 5'10" 225#. for the last year I have been riding a giant trance with juicy 5s 180mm front rotor and 160 rear. I am running dot 4 in the front and 5.1 in the rear(I ran out of 4 and had to go buy 5.1) Last year I put on a set of disco brake pads that I bought on ebay. they are semi metallic on front and back. Today I was on a steep section of trail and they absolutely faded out. I had both brakes locked and it was like I they were not there. Font rotor was purple. I have ridden two xc races on these and did a day at whistler last year with no problems!( I bled the brakes right before whistler)

    Does anyone have any ideas on what I could do to prevent this from happening again. I am wondering if rode the brake too much however the fact that this did not happen at whistler has me wondering. I am going to re bleed but was wondering if maybe ceramic pads may help. Has anyone tried them? Does it sound like my brakes are under spec?

  2. #2
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    If your lever feels solid then it's just pad fade. You can go for bigger rotor and/or high temp pads such a sintered metallic. I've read that ceramic pads are better than semi-mets for extreme applications but I haven't tried to cook them in the same setup yet so I can't say.

  3. #3
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    Even at 225# the brakes should work just fine. I would flush out the brakes. AVID says that the Juicy 5 & 7 require Dot 5.1 fluid only; the Juicy 3 uses Dot 4.

    Also make sure they are bleed correctly, it sound you might just have an air bubble somewhere in the line. I experienced brake fade similar to what you experience with my car once. As soon as the temp goes up the brake power disappears.

  4. #4
    Meh.
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    The J5 and J7 can use DOT 4 or 5.1. There are DOT 4s with higher boiling points than DOT 5.1 (Motul RBF600).

    Even though the lever is firm, the fluid may be old and absorbed a lot of moisture. This would lower the boiling point.

  5. #5
    I think I need to Upgrade
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    Quote Originally Posted by mtiny83
    Alright, I am 5'10" 225#. for the last year I have been riding a giant trance with juicy 5s 180mm front rotor and 160 rear. I am running dot 4 in the front and 5.1 in the rear(I ran out of 4 and had to go buy 5.1) Last year I put on a set of disco brake pads that I bought on ebay. they are semi metallic on front and back. Today I was on a steep section of trail and they absolutely faded out. I had both brakes locked and it was like I they were not there. Font rotor was purple. I have ridden two xc races on these and did a day at whistler last year with no problems!( I bled the brakes right before whistler)

    Does anyone have any ideas on what I could do to prevent this from happening again. I am wondering if rode the brake too much however the fact that this did not happen at whistler has me wondering. I am going to re bleed but was wondering if maybe ceramic pads may help. Has anyone tried them? Does it sound like my brakes are under spec?

    It may be time for a fluid flush. How worn down are the pads? The more they wear down the less ability they have to shed or release heat. Your rotors are probably glazed now also. I would replace pads, fluid and sand the braking surface down on the rotors.

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