Brakejack and rotor size- Mtbr.com
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  1. #1
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    Brakejack and rotor size

    Hello. Does a bigger rotor will reduce brakejack an a single pivot bike. Im currently running 160 on my santacruz heckler and definetly have some brakejack. Any thoughts???

    Bernardo

  2. #2
    meh....
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    i think IF you could feel the difference, the bigger rotor would increase brake jack. it's a longer pry bar, sort of.

  3. #3
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    Quote Originally Posted by bernardo
    Hello. Does a bigger rotor will reduce brakejack an a single pivot bike. Im currently running 160 on my santacruz heckler and definetly have some brakejack. Any thoughts???

    Bernardo
    from my experience, also on a heckler, with 160 and 180 rotors, size doesnt matter.

  4. #4
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    Quote Originally Posted by Monte
    i think IF you could feel the difference, the bigger rotor would increase brake jack. it's a longer pry bar, sort of.
    He read about brake jack on the internet, therefore he experiences it and needs a solution.
    Grit, spit, and a whole lot of duct tape!

  5. #5
    Bicyclochondriac.
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    Quote Originally Posted by bernardo
    Hello. Does a bigger rotor will reduce brakejack an a single pivot bike. Im currently running 160 on my santacruz heckler and definetly have some brakejack. Any thoughts???

    Bernardo

    I don't see how it would make any difference, other than the fact that you can brake harder. I would think that for the same amount of braking, the forces are all going in the same directions and it would feel the same. The axle, brake mounts, and pivots are all in the same place.

    BTW, I think brake "squat" is a better description of what a Heckler does.

    To those folks claiming this is not detectable, if you own a Heckler and an FSR design bike back to back (like I did), the difference in the braking traction is pretty noticeable.

  6. #6
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    I posted this last week in the all mountain forum; I ride regulary with a couple of guys that own specialized pitch and a giant reign and the only aspect that IMO their bikes are better than my SC heckler are staying active under braking, we have switched bikes for the same DH and this is noticeable. Im not saying that the pitch and the reign are better bikes, just that the suspension stays plusher under heavy braking.

    Bernardo

  7. #7
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    Brake jack is a phenomenon due to a torque moment generated by the brake/wheel on the swing arm when using the rear brake. Given the same braking force on the vehicle this torque moment is completely independent of rotor size.

    Increasing rotor size just makes it easier for your fingers to generate that braking force due to the extra leverage.

  8. #8
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    Use your front brake more, and worry less about brake jack.

  9. #9
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    Quote Originally Posted by RandyBoy
    Use your front brake more, and worry less about brake jack.
    Great insight on his question

  10. #10
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    So you would really consider compromising your braking power, thus safety, in order to try and make up for deficiencies in a suspension design? It sounds to me like it's time for someone to go frame shopping...

  11. #11
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    Quote Originally Posted by salimoneus
    So you would really consider compromising your braking power, thus safety, in order to try and make up for deficiencies in a suspension design? It sounds to me like it's time for someone to go frame shopping...
    Huh? He was thinking of getting a bigger rotor, not a smaller one. Besides, a 160 is plenty for the back.

  12. #12
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    Quote Originally Posted by kapusta
    Huh? He was thinking of getting a bigger rotor, not a smaller one. Besides, a 160 is plenty for the back.
    Lol yep you're right, I guess he was using the old double reverse logic and caught me napping

  13. #13
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    Quote Originally Posted by essenmeinstuff
    Brake jack is a phenomenon due to a torque moment generated by the brake/wheel on the swing arm when using the rear brake. Given the same braking force on the vehicle this torque moment is completely independent of rotor size.

    Increasing rotor size just makes it easier for your fingers to generate that braking force due to the extra leverage.
    What he said

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