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  1. #1
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    spke tension, values on one side are off by up to 50%

    hi,


    just ordered a pre build front wheel, deore xt hub, dt swiss fr750 and saphim spokes.

    measuring one side of the wheel, the parside tm-1 shows me these values:


    spoke number / parside reading
    1 19
    2 14
    3 9
    4 13
    5 13
    6 14
    7 9
    8 12
    9 16
    10 11
    11 8
    12 12
    13 13
    14 10
    15 11
    16 8



    the lowest value is 8, the highest 19 - is this to be expected?
    i can of course adjust the spokes, but what value should all of them have?

  2. #2
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    It's normal for a poorly built wheel. Part of the building process includes balancing the tension between adjacent spokes. You shouldn't have a 9 next to a 14 and 12.

    How out of round is your wheel? (vertical wheel hop)

    On the last wheel I built, this was the NDS tension just before my last step of tension balancing / truing touchup. I could have stopped here:

    16.5
    17.5
    17.5
    16.5
    17.5
    17.5
    17.5
    17
    17.5
    18
    17
    17
    18
    17.5

  3. #3
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    That is very uneven spoke tension and sign of a very shoddy wheel build. That 19 value could have been easily balanced out with the 8 value, just like the othe outlying high and low values. It should have been very evident with a simple pluck test to anyone that calls himself a wheelbuilder.

    I would get the spoke tension on that wheel balanced out by someone competent and never buy a wheel from those guys again.

  4. #4
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    just put it into the frame, turning it shows that it is about 1mm in hight that it jumps on one point and left/right looks almost perfect.

    from my amateur point of view its just the tension that is off.
    maybe they centered the wheel with a few rather larger turns on some spones rather tan more finely tuned ones on more spokes



    i suppose adjuting the tension on the spokes with the highest values a bit down would throw off the truing?
    or is it enough if you make it stiffer on one side to adjust the spoke on the other side a little less stiff?

  5. #5
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    How is the drive side tension?

  6. #6
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    let me check

    EDIT: the values above are for the front wheel on the side where the break IS NOT.

    gonna post the other side in a few minutes

  7. #7
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    The side of the wheel with the rotor is called the non drive side (NDS). The side of the wheel with cassette/crank/chain is called the drive side (DS).

  8. #8
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    ok so the first post was the NDS, and this is the DS:
    16,5
    17
    16,5
    15
    16
    14,5
    18
    16,5
    15
    14,5
    18
    15,5
    16
    15
    17
    11

  9. #9
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    Not great. I would probably dentension that wheel and start over.

    If you're not currently comfortable with the process and would like guidance, I would recommend this video: Master Wheel Building / Bill Mould Wheels

  10. #10
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    hm ok, but first. since 12 (tm-1) would be 1170NM and the rim can only hold 120NM, wouldnt it be possible to reduce the tension in 1/4 turns to get it at least down to not risk the rim?

    im also gonna write the manufactor with the values i measured. lets see if the wil readjust.

  11. #11
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    Quote Originally Posted by new_user67 View Post
    since 12 (tm-1) would be 1170NM and the rim can only hold 120NM, wouldnt it be possible to reduce the tension in 1/4 turns to get it at least down to not risk the rim?
    Your numbers are wrong ... you don't have ~10X the tension on the spokes as the rim can handle. The nipples would have pulled through the hole, or the spokes would have failed. You need to double check your values against the Park chart: http://www.parktool.com/assets/doc/p...conv-table.pdf

    The problem with not starting from zero, with such wildly uneven tension, is that you could spend just as much time trying to fix it, chasing changing values, than if you just did it right from the start. My hunch is that with a poor wheel build, you probably have a lot of spoke windup too, which will come out after you ride it, and it'll be laterally untrue.

    Here's a gross oversimplification of how I do it:

    I start by tensioning up the drive side the same number of turns ... say 15 turns on each DS nipple. When I get to 60-75% of final tension, I'll balance the tension, add some NDS tension, and get it laterally true. Then I add layers of tension on the DS to approach final tension. Between each layer of tension, I'm checking for tension balance and lateral true. Somewhere in there I'm adding NDS tension too, but that's mostly done during the dishing.

    PS> Don't work on the dish of a wheel if it's not laterally true.

  12. #12
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    yep, it is 1200NM. and youre right, i was in the wrong column for my spokes which are: Sapim CX-Ray 2.0/2.3-0.9/2.0

    but i dont know which column to choose in the steel blade section. doesnt really match anything.

    your plan sounds good....but whats "dishing"?

  13. #13
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    CX-Ray spokes are 0.9x2.2 at the blade. There's a column labeled accordingly.

    Dishing is the centering of the rim between ends of the hub.

  14. #14
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    ok thanks for all the replys guys, will wait what the manufacture says on monday.
    luckily i have a working front wheel that came with the bike, just wanted to exchange it because i broke the rear one....just to be safe.

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