Rear wheel R:L spoke tension ratio -- is it really ) 2:1 ???

Discussion in 'Cycling Equipment' started by Chuck, Jun 3, 2003.

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  1. Chuck

    Chuck Guest

    I'm a complete newby at making wheels, and I need help on one point.

    In reading Jobst Brandt's "The Bicycle Wheel", it tells how asymmetry makes spokes on the right side
    of a typical rear wheel (which has an 8 speed cassette in my case) at least twice as tight as ones
    on the left.

    In reading the instructions on my new Park tension meter, it claims that the recommended tension for
    spokes can be as low as 80Kgf , and as high as 130Kgf. If I were to maintain the typical > 2:1 ratio
    in order to center the rear wheel, this doesn't fit within the 80/130 range recommended by Park.

    To maintain this 2:1 ratio to center the wheel, one thing I could do is make the average tension on
    the left side of the wheel less than 65Kgf (which is what I'm doing now), with the right side being
    the max of 130Kgf.

    Alternatively, I could make the average tension on the right side greater than 160 Kgf, with the
    left side being Park's min of 80 Kgf.

    Finally, I could also split the difference (70/140).

    I'm probably over-analyzing this, but I want to do the right thing to have the most robust wheel.
    What do I do???

    Thanks, Chuck
     
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  2. "Chuck" <[email protected]> wrote in message news:<[email protected]>...
    > I'm a complete newby at making wheels, and I need help on one point.
    >
    > In reading Jobst Brandt's "The Bicycle Wheel", it tells how asymmetry makes spokes on the right
    > side of a typical rear wheel (which has an 8 speed cassette in my case) at least twice as tight as
    > ones on the left.
    >
    > In reading the instructions on my new Park tension meter, it claims that the recommended tension
    > for spokes can be as low as 80Kgf , and as high as 130Kgf. If I were to maintain the typical >
    > 2:1 ratio in order to center the rear wheel, this doesn't fit within the 80/130 range recommended
    > by Park.
    >
    > To maintain this 2:1 ratio to center the wheel, one thing I could do is make the average tension
    > on the left side of the wheel less than 65Kgf (which is what I'm doing now), with the right side
    > being the max of 130Kgf.
    >
    > Alternatively, I could make the average tension on the right side greater than 160 Kgf, with the
    > left side being Park's min of 80 Kgf.
    >
    > Finally, I could also split the difference (70/140).
    >
    > I'm probably over-analyzing this, but I want to do the right thing to have the most robust wheel.
    > What do I do???
    >
    > Thanks, Chuck

    Make the wheel as tight as the rim can stand. THE BOOK explains how to identify this point by stress
    relieving.

    Nigel Grinter
     
  3. Jan Hofland

    Jan Hofland Guest

    The tension of the non-drive side vs. the drive side is governed by the dishing of the wheel, which
    establishes the angles of the spokes relative to the axle. Don't worry about the ratio of the
    tensions. Get the dish right and adjust the drive side tension to about as much as you can without
    damage to the rim or flange.

    "Chuck" <[email protected]> wrote in message news:<[email protected]>...
    > I'm a complete newby at making wheels, and I need help on one point.
    >
    > In reading Jobst Brandt's "The Bicycle Wheel", it tells how asymmetry makes spokes on the right
    > side of a typical rear wheel (which has an 8 speed cassette in my case) at least twice as tight as
    > ones on the left.
    >
    > In reading the instructions on my new Park tension meter, it claims that the recommended tension
    > for spokes can be as low as 80Kgf , and as high as 130Kgf. If I were to maintain the typical >
    > 2:1 ratio in order to center the rear wheel, this doesn't fit within the 80/130 range recommended
    > by Park.
    >
    > To maintain this 2:1 ratio to center the wheel, one thing I could do is make the average tension
    > on the left side of the wheel less than 65Kgf (which is what I'm doing now), with the right side
    > being the max of 130Kgf.
    >
    > Alternatively, I could make the average tension on the right side greater than 160 Kgf, with the
    > left side being Park's min of 80 Kgf.
    >
    > Finally, I could also split the difference (70/140).
    >
    > I'm probably over-analyzing this, but I want to do the right thing to have the most robust wheel.
    > What do I do???
    >
    > Thanks, Chuck
     
  4. Chuck-<< Finally, I could also split the difference (70/140).

    I'm probably over-analyzing this, but I want to do the right thing to have the most robust wheel.
    What do I do???

    140kgf for the right side is too high for most rims. I say just build the wheel to 100 kgf for the
    right side, making sure it is round, true, dished and stress relieved and the left side pretty much
    takes care of itself.

    Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
    (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"
     
  5. Bobqzzi

    Bobqzzi Guest

    On Tue, 3 Jun 2003 21:04:38 -0700, "Chuck" <[email protected]> wrote:

    >I'm a complete newby at making wheels, and I need help on one point.
    >
    >In reading Jobst Brandt's "The Bicycle Wheel", it tells how asymmetry makes spokes on the right
    >side of a typical rear wheel (which has an 8 speed cassette in my case) at least twice as tight as
    >ones on the left.
    >
    >In reading the instructions on my new Park tension meter, it claims that the recommended tension
    >for spokes can be as low as 80Kgf , and as high as 130Kgf. If I were to maintain the typical >
    >2:1 ratio in order to center the rear wheel, this doesn't fit within the 80/130 range
    >recommended by Park.
    >
    >To maintain this 2:1 ratio to center the wheel, one thing I could do is make the average tension on
    >the left side of the wheel less than 65Kgf (which is what I'm doing now), with the right side being
    >the max of 130Kgf.
    >
    >Alternatively, I could make the average tension on the right side greater than 160 Kgf, with the
    >left side being Park's min of 80 Kgf.
    >
    >Finally, I could also split the difference (70/140).
    >
    >I'm probably over-analyzing this, but I want to do the right thing to have the most robust wheel.
    >What do I do???
    >
    >Thanks, Chuck
    >

    I went to 165kg on the right side spokes of my mavic T519 and have had no problems..but that is a
    very robust rim with sockets. If I remember right this let me get close to 100kg for the left side
    (I am using a 7 speed freehub).

    Bob
     
  6. Chuck

    Chuck Guest

    "Nigel Grinter" <[email protected]> wrote in message
    news:[email protected]...
    > Make the wheel as tight as the rim can stand. THE BOOK explains how to identify this point by
    > stress relieving.
    >
    > Nigel Grinter

    Nigel, I hear you! Keep in mind this is my first time at this, and I'm bound to mess something up. I
    can't be sure that I am stress relieving (squeezing hard enough) or observing things properly, in
    order to cause the wheel to "go untrue in two large waves" as the book describes. I'm looking for a
    way to cross-check using tension meter readings to see how I'm doing along the way.

    The Park Tension meter makes some recommendations for spoke tension range (80-130Kgf), and Jobst
    makes a statement that R:L tension ratio on the rear for typical wheels is about 2:1. These two
    things appeared to contradict one another, so I was at a loss as to how use the tension meter to
    cross-check my work.

    So the upshot is that I've already read the book and its techniques carefully. This question is
    about how to properly make use of a tension meter and its recommendations as a cross-check, given
    that I'm a total rookie at this.

    Thanks, Chuck
     
  7. Chuck

    Chuck Guest

    "Qui si parla Campagnolo" <[email protected]> wrote in message
    news:[email protected]...
    > 140kgf for the right side is too high for most rims. I say just build the
    wheel
    > to 100 kgf for the right side, making sure it is round, true, dished and
    stress
    > relieved and the left side pretty much takes care of itself.

    Thanks much Peter,

    I'll use 100Kgf as a guideline, being sure I don't wander too much above that during before final
    tensioning. When you personally perform your final tensioning, do you crank things up until the
    wheel "de-trues" during stress relieving, and then back off? Or alternatively, do you use a tension
    meter to set you upper limit?

    Chuck
     
  8. In article <[email protected]>, [email protected] says...
    >I'm a complete newby at making wheels, and I need help on one point. In reading Jobst Brandt's "The
    >Bicycle Wheel", it tells how asymmetry makes spokes on the right side of a typical rear wheel
    >(which has an 8 speed cassette in my case) at least twice as tight as ones on the left. In reading
    >the instructions on my new Park tension meter, it claims that the recommended tension for spokes
    >can be as low as 80Kgf , and as high as 130Kgf. If I were to maintain the typical > 2:1 ratio in
    >order to center the rear wheel, this doesn't fit within the 80/130 range recommended by Park. To
    >maintain this 2:1 ratio to center the wheel, one thing I could do is make the average tension on
    >the left side of the wheel less than 65Kgf (which is what I'm doing now), with the right side being
    >the max of 130Kgf. Alternatively, I could make the average tension on the right side greater than
    >160 Kgf, with the left side being Park's min of 80 Kgf. Finally, I could also split the difference
    >(70/140). I'm probably over-analyzing this, but I want to do the right thing to have the most
    >robust wheel. What do I do???

    I wouldn't worry about absolute numbers. What you want to do is build the wheel according to the
    book. That means that the drive side tension will be as high as the rim will allow. It could very
    well end up being a number higher than 130kgf. Also, the tension ratio that gets the rim centered
    over the hub may not be 2:1. bild the wheel and then you can see if you end up with
    2:1 and at what tension.
    -----------------
    Alex __O _-\<,_ (_)/ (_)
     
  9. "Chuck" <[email protected]> wrote in message news:<[email protected]>...
    > "Nigel Grinter" <[email protected]> wrote in message
    > news:[email protected]...
    > > Make the wheel as tight as the rim can stand. THE BOOK explains how to identify this point by
    > > stress relieving.
    > >
    > > Nigel Grinter
    >
    > Nigel, I hear you! Keep in mind this is my first time at this, and I'm bound to mess something up.
    > I can't be sure that I am stress relieving (squeezing hard enough) or observing things properly,
    > in order to cause the wheel to "go untrue in two large waves" as the book describes. I'm looking
    > for a way to cross-check using tension meter readings to see how I'm doing along the way.
    >
    > The Park Tension meter makes some recommendations for spoke tension range (80-130Kgf), and Jobst
    > makes a statement that R:L tension ratio on the rear for typical wheels is about 2:1. These two
    > things appeared to contradict one another, so I was at a loss as to how use the tension meter to
    > cross-check my work.
    >
    > So the upshot is that I've already read the book and its techniques carefully. This question is
    > about how to properly make use of a tension meter and its recommendations as a cross-check, given
    > that I'm a total rookie at this.
    >
    > Thanks, Chuck

    The trouble with being guided by just tension numbers is that rims vary a great deal in terms of how
    much tension they can tolerate: some will wimp out at quite low values, while others just cannot be
    taken to the point of imminent failure because the nipples start to round off. If possible, I like
    to get the left side spokes up to 70-80kgf. If the rim won't allow this, one way of reducing the
    liklihood of the non-drive spokes loosening in use is to build with thinner spokes on that side.

    Happy building.

    Nigel Grinter
     
  10. A Muzi

    A Muzi Guest

    > "Nigel Grinter" <[email protected]> , who knows something about this,
    wrote in message
    > news:[email protected]...
    > > Make the wheel as tight as the rim can stand. THE BOOK explains how to identify this point by
    > > stress relieving.

    "Chuck" <[email protected]> wrote in message news:[email protected]...
    > Nigel, I hear you! Keep in mind this is my first time at this, and I'm bound to mess something up.
    > I can't be sure that I am stress relieving (squeezing hard enough) or observing things properly,
    > in order to cause
    the
    > wheel to "go untrue in two large waves" as the book describes. I'm
    looking
    > for a way to cross-check using tension meter readings to see how I'm doing along the way.
    >
    > The Park Tension meter makes some recommendations for spoke tension range (80-130Kgf), and Jobst
    > makes a statement that R:L tension ratio on the
    rear
    > for typical wheels is about 2:1. These two things appeared to contradict one another, so I was at
    > a loss as to how use the tension meter to cross-check my work.
    >
    > So the upshot is that I've already read the book and its techniques carefully. This question is
    > about how to properly make use of a tension meter and its recommendations as a cross-check, given
    > that I'm a total rookie at this.

    Jobst's "2:1" ,while roughly true, should not be taken literally. Just as one cannot control both a
    quantity and a price, you are correct that the general advice you've been given would contradict if
    taken literally.

    Listen to Nigel and bring the wheel, centered over the locknuts, to the highest tension the rim can
    bear. The left side tension will be whatever it
    is. Since you cannot control that without screwing up the wheel's centering, ignore that left side
    tension value.

    Then when you are finished, use the tensiometer (when did it become a "tension meter"?) to amuse
    yourself. It is an interesting adjunct to wheelbuilding, not a requisite tool.
    --
    Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971
     
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