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  1. #1
    beautiful jackass
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    How crucial is torquing rotor bolts to spec on initial installation?

    On Tuesday my new wheels should be arriving and I've got new brakes and fresh rotors to install.

    I know pretty much every bolt on a bike has a specified torque value but I would imagine some exact measures are more important for some parts than others.

    Without using a torque wrench, will I encounter frustration installing rotors? Or can I just do it until they feel good and tight?

    If there's cause for concern I'll just bring the rotors to a bike shop and have them do it since I need to go anyway to get my new headset cups pressed and crown race set. But if I can do the rotors myself I'd rather save whatever amount they'd charge me to torque some bolts.

  2. #2
    ride hard take risks
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    I install each bolt then hand screw it till it contacts the rotor then working in a star type pattern snug each bolt evenly, you dont need to be a brute the bolts have Lock-Tite and have a tendency of staying tight.
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  3. #3
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    just make sure theyre tight. this isnt the case when over torquing can brake something.

  4. #4
    nnn
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    Rotor bolts require surprisingly little torque, try working it out compared to the size of your wrench and then emulating the effort required, you will be surprise how little it is.
    Evenly tightening helps against squeal and poor allignment, overtightening can strip the small bolt head and is not really required as forces on the rotor are perpendicular to the thread direction, unlike stems or bottom brackets etc
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  5. #5
    A wheelist
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    Quote Originally Posted by one incredible donkey
    How crucial is torquing rotor bolts to spec on initial installation? If there's cause for concern I'll just bring the rotors to a bike shop and have them do it since I need to go anyway to get my new headset cups pressed and crown race set. But if I can do the rotors myself I'd rather save whatever amount they'd charge me to torque some bolts.
    I'll go out on a limb and claim that the ratio of rotor bolts tightened with a normal wrench versus bolts torqued to specs with a torque wrench is about a zillion to one. I'm on about my tenth set of disc brakes over ten years and I don't even own a torque wrench.

    And who's to say the bike shop will use one too?

    Oh by the way, do that headset at home too.
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  6. #6
    Two wheels are best
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    Yeah...I installed quite a few rotors before I bought a torque wrench (I have three, now! ). Hasn't seemed to make much difference on the rotor bolts but, I torque them now...after all, I need to use them to justify having bought them!
    Never be afraid to try something new.

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  7. #7
    Dirt Deviant
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    I find it quite easy to rip the head off a rotor bolt if tightened too much....but I'm kind of a brute.
    I usually do snug ( in a star pattern) plus a 1/4 of a turn. No torque wrench.
    Look, whatever happens, don't fight the mountain.

  8. #8
    beautiful jackass
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    Excellent - I am going to do it myself. Thanks for the confidence

    Quote Originally Posted by Mike T.
    Oh by the way, do that headset at home too.
    I considered it, and even went so far as to grab a scrap piece of copper tubing for the remover. But I'm honestly concerned about damaging the headset or not doing it right.

  9. #9
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    I've torqued my own rotors (no problems yet), don't own a torque wrench either (yet).

  10. #10
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    Bolt Torque

    The answer is very simple - if you want to do it properly, get a torque wrench.
    The torque setting on a bolt is to get the correct elastic stretch in the bolt to maintain clamping force.
    Without a torque wrench and depending on how ham fisted you are, you're either
    1. not going to get enough tension in the bolt to maintain clamping force, or
    2. over torque the bolt and yield it leading to inadequate joint clamping force
    Adding loctite changes the friction characteristics and therefore the clamping force for a given torque setting. ie don't use loctite on a bolt system unless it has been designed to use loctite and the torque setting adjusted accordingly.
    This is why companies employ engineers and have specific instructions on how parts should be assembled. If you don't do per the instructions and it goes wrong, don't blame the manufacturer...

  11. #11
    Riding a Rig.
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    Quote Originally Posted by one incredible donkey
    I considered it, and even went so far as to grab a scrap piece of copper tubing for the remover. But I'm honestly concerned about damaging the headset or not doing it right.
    Its super easy to do. Just go slow and you won't have any problems.
    "Physics is timeless. Marketing and bs never lasts. Thats been proven time and time again."
    -Dave Weagle

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