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  1. #1
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    truing a rotor effectively

    I have a front rotor which has a warp to it (It is an Avid clean sweep G2 - 203 mm). I can both feel it when braking (via lever) and see it when I put the wheel on a truing stand.

    I have spent a lot of time trying to bend out the warp, a pair of adjustable wrenches, and even trying a bench vise. I was successful at eliminating most of the original warp, but cannot see to get rid of the rest (maybe one to two mm). every time I bend it, it seems to just spring back to the same position. to make it worse, part of the bend is in the "spoke" part of the rotor, which is hard to reach with the adjustable wrench.

    any tips on ways to finish the job? would heating the rotor help? would commercial truing forks (e.g. park's tw-2) help much?

  2. #2
    Lionel Hutz, Esq.
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    The Park rotor truing tool (DT-2) is pretty good. I've been using one for about a year. It's got a deep enough slit in it to effect the rotor spokes. I find that the shape of the tool opens up the range and accuracy of the adjustments.

    The TW-2 is a torque wrench. I guess you could use a torque wrench to true your rotor somehow, but it seems like a lot of wasted effort. Although it might be interesting to know that 60in-lbs of force will get a particular bend out of a rotor, I doubt it will be much help it future repairs.

    If you have a truing stand, the DT-3 rotor truing guage works well. Or you could fashion a make-shift substitute. Hard to beat the tools designed for the job, in my opinion.
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  3. #3
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    Quote Originally Posted by spoke2spoon
    every time I bend it, it seems to just spring back to the same position.
    If it is springing back to the same position, you haven't gone far enough. Bend more.

    Don't heat it.

  4. #4
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    Quote Originally Posted by Thirdrawn
    The TW-2 is a torque wrench. I guess you could use a torque wrench to true your rotor somehow, but it seems like a lot of wasted effort. Although it might be interesting to know that 60in-lbs of force will get a particular bend out of a rotor, I doubt it will be much help it future repairs.
    my bad! I certainly intended to ask about truing forks, but hey, at this point I'll try anything that might work. [maybe I should ask David Letterman to run over it with his steam roller!]

  5. #5
    Bandolero Crew N.M.
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    A new rotor may be the way to go. Done deal. Slap it on and your off. Bent rotors tend to never be the same.

  6. #6
    discombobulated SuperModerator
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    Quote Originally Posted by gmcttr
    If it is springing back to the same position, you haven't gone far enough. Bend more.
    Don't heat it.
    Ive bent things very straight, though I used indicators to watch travel. Then I would gauge the item for straightness and re-bend to a point somewhat further than the initial press. you can get real good results like this with patience. I might make some kind of rotor truing thing for the garage..a spindle with a mounting block, a cheap travel indicator.....hmmmmmmmmmm

    I would like to add, you cannot simply grab a rotor and bend it ....The points where the deviation begins and ends should somehow be supported

  7. #7
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    On a related note.. has anyone found a particular rotor to be especially hearty? I'm really tired of getting little dings out of the blue. avid rotors seem kind of soft or is this every rotor?
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  8. #8
    ride hard take risks
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  9. #9
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    Tougher rotor

    I find the Galfer rotor I have tougher than the Avids I have used. The Galfer came slightly out of true once and it took a lot more force to bend it back into shape then the Avids ever did. Plus if I heard the Avid bang against a rock, even lightly, it would be out of true. Not so with the Galfer. BTW, I don't work for Galfer.

  10. #10
    ride hard take risks
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    Quote Originally Posted by KeithM
    I find the Galfer rotor I have tougher than the Avids I have used. The Galfer came slightly out of true once and it took a lot more force to bend it back into shape then the Avids ever did. Plus if I heard the Avid bang against a rock, even lightly, it would be out of true. Not so with the Galfer.

    I'll drink to that.
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  11. #11
    A wheelist
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    By far the best tools for rotor truing are the original tools for the job, the Morningstar Drumstix. They come as a set of three and are used together with two of the tools isolating the warp and the third one doing the bending.

    The three tools used together allow much finer adjustment than a single tool or an adjustable wrench.

    Used with or without Paul Morningstar's R2OC-Tech dial indicator tool they allow you to do a perfect truing job.

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  12. #12
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    A bent rotor that has a "set" to it can be straightened

    Hello, The problem you describe can be "ironed" out using three levers. I've found that using the morningstar drumstix are the way to go. Buying a new rotor does not always solve the problem and when you buy a tool - you have it for life. If you ride hard you will be prnging rotors periodically.
    check out utah mounating biking fix it section and ride on !

  13. #13
    ride hard take risks
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    And with Galfer rotors you wont need to true them every day.
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  14. #14
    Suffers From Binge Biking
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    Quote Originally Posted by dogonfr
    And with Galfer rotors you wont need to true them every day.
    Where might one find the Galfer rotor? A search of Jenson, Pricepoint, and Ebay all come up empty (except for motorcycle rotors).
    If it ain't broke, fix it 'till it is.

  15. #15
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    Quote Originally Posted by marsh rider
    Where might one find the Galfer rotor? A search of Jenson, Pricepoint, and Ebay all come up empty (except for motorcycle rotors).
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  16. #16
    ride hard take risks
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    Quote Originally Posted by marsh rider
    Where might one find the Galfer rotor? A search of Jenson, Pricepoint, and Ebay all come up empty (except for motorcycle rotors).
    Also your LBS can order from BTI.

    http://www.bti-usa.com/public/manufacturer/GL/BR
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  17. #17
    mtbr member
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    thanks for all the info, this was great!!!

  18. #18
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    Quote Originally Posted by Douglas Fir
    Hello, The problem you describe can be "ironed" out using three levers. I've found that using the morningstar drumstix are the way to go. Buying a new rotor does not always solve the problem and when you buy a tool - you have it for life. If you ride hard you will be prnging rotors periodically.
    check out utah mounating biking fix it section and ride on !
    Quit the sham and post under your real name Paul....
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  19. #19
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    What ever

    Quote Originally Posted by BrokenSpokes
    Quit the sham and post under your real name Paul....

    Paul or not Morningstar stuff is simply the best there is for it's application.
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  20. #20
    A wheelist
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    Quote Originally Posted by danoalb
    Paul or not Morningstar stuff is simply the best there is for it's application.
    I've got 4-5 Morningstar gizmos and they all work as advertized - really well. Give us more PM!
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