Proper Spoke tension

Discussion in 'Cycling Equipment' started by bcsst26, Mar 12, 2005.

  1. bcsst26

    bcsst26 New Member

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    I am truing my rear wheel. I have alexrims AT400. I was wandering the proper spoke tension for each side of the wheel. I have a tension meter so I would like to try and get it pretty accurate. I looked around but can't find the specifics for the AT400 rims. I found one site that said 110kfg for drive side and 70kfg for the nondrive. I was wandering if someelse had any advice to help me out.
     
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  2. melli

    melli New Member

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    I built my rear wheel with an open pro rim and dt revolution spokes both sides. The readings i got were 108 on the drive side and 75 on the non drive side. I'm unsure of these tensions for the spokes are quite thin 2.0 1.5 2.0. Have you had any luck finding tensions for build up wheels? I'm curious as well for I need some help in this topic.
     
  3. daveornee

    daveornee New Member

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    [email protected]
    shoould give you a response.
    Most manufacturers give these specifications out through their distributors.
     
  4. 53-11

    53-11 New Member

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    You know I've seen custom builders do things to equalize the tension out.

    Besides using an aymetric rim,

    I've seen guys use thinner guage spokes on the non-drive compared to the drive side. I've also seen 2x cross/3x cross used on opposite sides.

    Any idea on how this impacts the tensions?
     
  5. Weisse Luft

    Weisse Luft New Member

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    Indeterminate on the impact of varying spoke gauge on dished wheels. What works on one wheel may be different opn another if even the lacing is varied.

    The general rule is the wheel must never lose spoke tension when loaded to the limit. Heavier riders need more tension, weaker rims need more spoke elasticity. Lower spoke counts require more spoke elasticity and greater tension.

    The best bet is to get a helper to measure tensions while loading the bike in all possible static conditions like seated, standing, leaning etc. No spoke should ever go slack, that being tension should never fall off scale, about 20 kgf should remain on the drive side spokes. More importantly, you need at least 10 kgf on the non-drive side.

    You can generally get away with 100 KGF on the front wheel spokes but the rear wheel is always tricky.
     
  6. artmichalek

    artmichalek New Member

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    Like Wiesse Luft said, the effects varry from wheel to wheel. Rear wheels can get a little complicated. The spoke choice for the drive side has as much to do with torsional stiffness as it does with tension balance. You typically won't, or at least shouldn't, see thin or butted spokes on the drive side because it will make the wheel particularly spongy under hard pedaling. As for lacing patterns, putting fewer crosses on the non-drive side decreases the spoke length to be closer to that of the drive side. There are some wheels out there that have radial drive sides and 2x non-drive sides, but I still can't figure out why anyone would do this.
     
  7. daveornee

    daveornee New Member

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    Thinner guage spokes have no impact on tension. The amount of tension in the wheel is the same when using thinner guage non-drive side spokes. However, the amount of stretch in the thinner guage non-drive side spokes is greater, all else held the same. The benefit to more stretch using thinner guage non-drive side spokes is they will not go slack for the same amount of force on the rim. It is possible to attain nearly the same amount of stretch between the drive side and non-drive side spokes by using thinner guage non-drive side spokes.

    Crossing patterns effect spoke support angles when all else is held the same. Tangential spoking has lower spoke support angle, while radial spoking has the highest spoke support angle with heads in configuration. If I use an example of a Mavic Open Pro 700C rim, 32 spoke Shimano 8/9 speed rear hub with 3X on the drive side and radial on the non-drive side:
    Drive side spokes have an average spoke support angle of 4.1 degrees, while non-drive radial spoking has 9.3 degrees if the heads are in and 5.8 degrees if the heads are out. Spoke support angle differences from side-to-side determine the force vectors for spoke tension differences. In the above examples, the preferred way to attain closer spoke tension would be to use the head out radial spoke pattern on the non-drive side. Differences in spoke support angles 3X to 2X in this example is 0.1 degree. It is desireable to balance the spoke tensions in the rear wheel and help spread the dynamic loading on the wheel more evenly. There is a lot more to the story. Many Shimano hubs are not waranteed for radial spoking.
    The asymetric rim is an easy way to help the situation in rear and disc wheels.
     
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