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Info from wheelbuilder.com site

Started by Mike Jacoubowsky · · Last activity · 31 posts · 1,173 views

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Cycling Equipment
Published
7 January 2007
Last activity
28 January 2007
Original author
Mike Jacoubowsky
Posts
31
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  1. http://www.wheelbuilder.com/tips/Spokes.asp
    "As the number of spoke crossings increase the angle in which each spoke
    leaves the hub approaches 90o (tangential). Wheels with 3x or 4x lace
    patterns will usually transfer power more efficiently than those with 2x
    patterns. As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which is
    about 5%, actually contribute to a difference you can feel?

    #2: How does "lower lateral stiffness" improve cornering stability?

    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com

  2. Who are these knuckleheads??

    Mike Jacoubowsky said:

    http://www.wheelbuilder.com/tips/Spokes.asp
    "As the number of spoke crossings increase the angle in which each spoke
    leaves the hub approaches 90o (tangential). Wheels with 3x or 4x lace
    patterns will usually transfer power more efficiently than those with 2x
    patterns. As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which is
    about 5%, actually contribute to a difference you can feel?

    #2: How does "lower lateral stiffness" improve cornering stability?

    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com

  3. Mike Jacoubowsky said:

    http://www.wheelbuilder.com/tips/Spokes.asp
    "As the number of spoke crossings increase the angle in which each spoke
    leaves the hub approaches 90o (tangential). Wheels with 3x or 4x lace
    patterns will usually transfer power more efficiently than those with 2x
    patterns. As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which is
    about 5%, actually contribute to a difference you can feel?

    you mean the difference between radial and tangential spoking? some
    people say they can feel it. others not. does it matter?

    Quoted message said:


    #2: How does "lower lateral stiffness" improve cornering stability?

    it doesn't actually say "it improves it", it says lateral stiffness is
    important, but doesn't state the sense. lateral stiffness /can/ be
    important if the rider jockeys or the frame is not very stiff
    torsionally [shimmy], and stiffer is better.

    i guess your objective in this post is to illustrate misinformation
    and/or ambiguity. if so, do you have a position on the subject or do
    you just want to stir the pot?

  4. Mike Jacoubowsky said:

    http://www.wheelbuilder.com/tips/Spokes.asp
    "As the number of spoke crossings increase the angle in which each spoke
    leaves the hub approaches 90o (tangential). Wheels with 3x or 4x lace
    patterns will usually transfer power more efficiently than those with 2x
    patterns. As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which is
    about 5%, actually contribute to a difference you can feel?

    #2: How does "lower lateral stiffness" improve cornering stability?

    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com

    Dear Mike,

    Damon Rinard has tested 140 wheels for lateral stiffness by mounting
    them horizontally in a machine table rig, hanging a 25-lb weight, and
    measuring how far the rim drops with a micrometer:

    http://www.sheldonbrown.com/rinard/wheel/data.htm

    He points out that this 25-lb force is more than the wheel is likely
    to experience in cornering.

    The wheels deflect only 0.97 to 5.23 mm with this heavy lateral load.

    Most wheels tested are around 2 mm (the 5.23 mm is an oddball plastic
    spoked wheel), so the typical difference is about 1 mm.

    It's unlikely that any rider could tell any difference between the
    wheels in blind testing of cornering (hard to arrange blindness with a
    wheel, but big fenders might work wonders).

    The page is well worth a look.

    Cheers,

    Carl Fogel

  5. In article <[email hidden]>,

    Mike Jacoubowsky said:

    http://www.wheelbuilder.com/tips/Spokes.asp "As the number of spoke
    crossings increase the angle in which each spoke leaves the hub
    approaches 90o (tangential). Wheels with 3x or 4x lace patterns will
    usually transfer power more efficiently than those with 2x patterns.
    As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to
    decreased radial stiffness, which improves ride quality.
    Consequently wheels with more spoke crossings have lower lateral
    stiffness, which is important to cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm,
    which is about 5%, actually contribute to a difference you can feel?

    #2: How does "lower lateral stiffness" improve cornering stability?

    Wait, it gets better:

    "Tension is simply the load applied to spokes by tightening the
    nipples. Consider each spoke to be a long slender bolt connecting the
    hub to the rim with a fastening nut called the nipple. Spokes behave
    similar to bolts in that they stretch and use the energy held in the
    material to resists the complex dynamic loads created by the rider and
    the road. Spoke tension cannot be determined by visually inspecting a
    wheel and is often independent of wheel trueness. Evaluation and
    balancing of spoke tension with a Tensiometer can be time consuming and
    add very little to the aesthetic trueness of a wheel. For this reason
    spoke tension is neglected by many bicycle mechanics. Wheelbuilder
    carefully monitors spoke tension during our build process to ensure an
    even distribution of load through the entire wheel structure. During
    the final truing process all spoke tensions are input into our own
    software for a statistical comparison. We do not ship wheels with
    spoke tension variations outside of our close tolerance. A well
    balanced hand built wheel will outperform and outlast any machine built
    wheel. Additionally it will feel more responsive and stay true for
    thousands of miles."

    A mix of accurate statements and mumbo-jumbo, which is to be found
    throughout the site. Yikes.

  6. Mike Jacoubowsky said:

    http://www.wheelbuilder.com/tips/Spokes.asp
    "As the number of spoke crossings increase the angle in which each spoke
    leaves the hub approaches 90o (tangential). Wheels with 3x or 4x lace
    patterns will usually transfer power more efficiently than those with 2x
    patterns. As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which is
    about 5%, actually contribute to a difference you can feel?

    #2: How does "lower lateral stiffness" improve cornering stability?

    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com

    Hype nowithstanding, goods and others about the site-

    -wheelbuilders-good
    -pricing-not bad altho only 14g straight DT spokes PLUS $.09 for brass
    nipps(they come with the spokes)
    -lots of choices-good altho sounds like they'll build anything,
    regardless of how silly
    -hub choices-disappointing..DT, good, BUT none of the best hubs there
    are-Campagnolo and shimano

    I think anybody that still builds wheels, from scratch, is good. And if
    people will listen, they will learn the resulting wheels are big on
    performance, reliability but low on hype and price.

  7. Quoted message said:
    Quoted message said:

    #2: How does "lower lateral stiffness" improve cornering stability?

    it doesn't actually say "it improves it", it says lateral stiffness is
    important, but doesn't state the sense. lateral stiffness /can/ be
    important if the rider jockeys or the frame is not very stiff torsionally
    [shimmy], and stiffer is better.

    i guess your objective in this post is to illustrate misinformation and/or
    ambiguity. if so, do you have a position on the subject or do you just
    want to stir the pot?

    No, my objective was to find out what people thought about the idea that
    too-much lateral stiffness is a bad thing. This is a new one to me. To the
    best of my knowledge, people here and elsewhere have tended towards
    stiffer=stronger=better for most things having to do with wheels.
    Intuitively, I'd think that lateral stiffness would enhance cornering. But
    re-reading the paragraph in question-

    "As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    - Perhaps I had it backward, and they're saying that lateral stiffness, not
    lower lateral stiffness, is a good thing?

    I have my own opinions, but I learn a lot more when I listen to what other
    people have to say about something than when I'm trying to defend myself.

    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com

    "jim beam" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:
    Mike Jacoubowsky said:

    http://www.wheelbuilder.com/tips/Spokes.asp
    "As the number of spoke crossings increase the angle in which each spoke
    leaves the hub approaches 90o (tangential). Wheels with 3x or 4x lace
    patterns will usually transfer power more efficiently than those with 2x
    patterns. As the number of spoke crossings increase the length of each
    spoke increases. Longer spokes are more flexible and contribute to
    decreased radial stiffness, which improves ride quality. Consequently
    wheels with more spoke crossings have lower lateral stiffness, which is
    important to cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which is
    about 5%, actually contribute to a difference you can feel?

    you mean the difference between radial and tangential spoking? some
    people say they can feel it. others not. does it matter?

    Quoted message said:


    #2: How does "lower lateral stiffness" improve cornering stability?

    it doesn't actually say "it improves it", it says lateral stiffness is
    important, but doesn't state the sense. lateral stiffness /can/ be
    important if the rider jockeys or the frame is not very stiff torsionally
    [shimmy], and stiffer is better.

    i guess your objective in this post is to illustrate misinformation and/or
    ambiguity. if so, do you have a position on the subject or do you just
    want to stir the pot?

  8. Mike Jacoubowsky said:
    Quoted message said:
    Quoted message said:

    #2: How does "lower lateral stiffness" improve cornering stability?

    it doesn't actually say "it improves it", it says lateral stiffness is
    important, but doesn't state the sense. lateral stiffness /can/ be
    important if the rider jockeys or the frame is not very stiff
    torsionally [shimmy], and stiffer is better.

    i guess your objective in this post is to illustrate misinformation
    and/or ambiguity. if so, do you have a position on the subject or do
    you just want to stir the pot?

    No, my objective was to find out what people thought about the idea that
    too-much lateral stiffness is a bad thing. This is a new one to me. To
    the best of my knowledge, people here and elsewhere have tended towards
    stiffer=stronger=better for most things having to do with wheels.
    Intuitively, I'd think that lateral stiffness would enhance cornering.
    But re-reading the paragraph in question-

    "As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    - Perhaps I had it backward, and they're saying that lateral stiffness,
    not lower lateral stiffness, is a good thing?

    I have my own opinions, but I learn a lot more when I listen to what
    other people have to say about something than when I'm trying to defend
    myself.

    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com


    I don't think this idea is entirely novel (which is not to say that it has
    any merit).

    I used to have a wheelbuilding book that made a similar claim. I think
    this is it, though I can't be sure without seeing the cover:

    http://tinyurl.com/yehrz7

    The book had two drawings of a swimmer bouncing on the end of a diving
    board. In one, the board was short; in the other, long. One could see from
    the cartoon motion marks that the long board was deflecting more. The
    author's conclusion was that long spokes are cushier.

    Quoted message said:

    "jim beam" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:
    Mike Jacoubowsky said:

    http://www.wheelbuilder.com/tips/Spokes.asp "As the number of spoke
    crossings increase the angle in which each spoke leaves the hub
    approaches 90o (tangential). Wheels with 3x or 4x lace patterns will
    usually transfer power more efficiently than those with 2x patterns.
    As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to
    decreased radial stiffness, which improves ride quality. Consequently
    wheels with more spoke crossings have lower lateral stiffness, which
    is important to cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which
    is about 5%, actually contribute to a difference you can feel?

    you mean the difference between radial and tangential spoking? some
    people say they can feel it. others not. does it matter?

    Quoted message said:

    #2: How does "lower lateral stiffness" improve cornering stability?

    it doesn't actually say "it improves it", it says lateral stiffness is
    important, but doesn't state the sense. lateral stiffness /can/ be
    important if the rider jockeys or the frame is not very stiff
    torsionally [shimmy], and stiffer is better.

    i guess your objective in this post is to illustrate misinformation
    and/or ambiguity. if so, do you have a position on the subject or do
    you just want to stir the pot?

  9. Mike Jacoubowsky said:
    Quoted message said:
    Quoted message said:

    #2: How does "lower lateral stiffness" improve cornering stability?


    it doesn't actually say "it improves it", it says lateral stiffness is
    important, but doesn't state the sense. lateral stiffness /can/ be
    important if the rider jockeys or the frame is not very stiff torsionally
    [shimmy], and stiffer is better.

    i guess your objective in this post is to illustrate misinformation and/or
    ambiguity. if so, do you have a position on the subject or do you just
    want to stir the pot?

    No, my objective was to find out what people thought about the idea that
    too-much lateral stiffness is a bad thing. This is a new one to me. To the
    best of my knowledge, people here and elsewhere have tended towards
    stiffer=stronger=better for most things having to do with wheels.
    Intuitively, I'd think that lateral stiffness would enhance cornering. But
    re-reading the paragraph in question-

    "As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    - Perhaps I had it backward, and they're saying that lateral stiffness, not
    lower lateral stiffness, is a good thing?

    I have my own opinions, but I learn a lot more when I listen to what other
    people have to say about something than when I'm trying to defend myself.

    lateral stiffness is better for [reducing] shimmy and leads to a more
    "stable" feel. but it goes hand in hand with radial stiffness, and too
    much of that can be uncomfortable for the rider.

    Quoted message said:


    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com

    "jim beam" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:
    Mike Jacoubowsky said:

    http://www.wheelbuilder.com/tips/Spokes.asp
    "As the number of spoke crossings increase the angle in which each spoke
    leaves the hub approaches 90o (tangential). Wheels with 3x or 4x lace
    patterns will usually transfer power more efficiently than those with 2x
    patterns. As the number of spoke crossings increase the length of each
    spoke increases. Longer spokes are more flexible and contribute to
    decreased radial stiffness, which improves ride quality. Consequently
    wheels with more spoke crossings have lower lateral stiffness, which is
    important to cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which is
    about 5%, actually contribute to a difference you can feel?


    you mean the difference between radial and tangential spoking? some
    people say they can feel it. others not. does it matter?

    Quoted message said:

    #2: How does "lower lateral stiffness" improve cornering stability?


    it doesn't actually say "it improves it", it says lateral stiffness is
    important, but doesn't state the sense. lateral stiffness /can/ be
    important if the rider jockeys or the frame is not very stiff torsionally
    [shimmy], and stiffer is better.

    i guess your objective in this post is to illustrate misinformation and/or
    ambiguity. if so, do you have a position on the subject or do you just
    want to stir the pot?

  10. jim beam said:

    lateral stiffness is better for [reducing] shimmy and leads to a more
    "stable" feel. but it goes hand in hand with radial stiffness, and too
    much of that can be uncomfortable for the rider.

    On rear wheels at least, the lateral stiffness can be enhanced by
    increasing the flange spacing... but then you need to go to a G3 style
    lacing to get reasonable tension in the NDS spokes... but that is kinda
    nice too, since now those spokes won't go slack from side loads...
    *but* you don't have any better lateral stiffness than before. So I
    guess I agree with you.

    I must not be sensitive though... I can't tell the difference in radial
    or lateral stiffness from one wheel to the next.

  11. Mike Jacoubowsky said:

    - Perhaps I had it backward, and they're saying that lateral stiffness, not
    lower lateral stiffness, is a good thing?

    I think they are saying that there is no free lunch... ie high lateral
    stiffness is good for cornering, but bad for ride smoothness.
    Personally, I think they are both insignificant effects. What you want
    in a wheel is enough strength and durability so that the rim doesn't
    taco and the spokes don't break. These qualities are weakly correlated
    with stiffness. Maybe a wheel with poor lateral stiffness can induce
    shimmy, but I've not experienced this.

  12. Ron Ruff said:
    jim beam said:

    lateral stiffness is better for [reducing] shimmy and leads to a more
    "stable" feel. but it goes hand in hand with radial stiffness, and too
    much of that can be uncomfortable for the rider.

    On rear wheels at least, the lateral stiffness can be enhanced by
    increasing the flange spacing...

    hard to do if you want to use a typical cassette hub. there's small
    variations from maker to maker, but the max tension ratio difference
    you'll get between them all is about 15%. using thicker drive side
    spokes works though. stiffer rim does too.

    Quoted message said:

    but then you need to go to a G3 style
    lacing to get reasonable tension in the NDS spokes...

    tension does not affect elasticity.

    Quoted message said:

    but that is kinda
    nice too, since now those spokes won't go slack from side loads...
    *but* you don't have any better lateral stiffness than before. So I
    guess I agree with you.

    I must not be sensitive though... I can't tell the difference in radial
    or lateral stiffness from one wheel to the next.

  13. Ron Ruff said:
    Mike Jacoubowsky said:

    - Perhaps I had it backward, and they're saying that lateral stiffness, not
    lower lateral stiffness, is a good thing?

    I think they are saying that there is no free lunch... ie high lateral
    stiffness is good for cornering, but bad for ride smoothness.
    Personally, I think they are both insignificant effects. What you want
    in a wheel is enough strength and durability so that the rim doesn't
    taco and the spokes don't break. These qualities are weakly correlated
    with stiffness. Maybe a wheel with poor lateral stiffness can induce
    shimmy, but I've not experienced this.


    it doesn't induce it, but it's part of the shimmy equation. torsional
    frame stiffness and [rear] wheel lateral stiffness both affect the
    harmonic frequency of the shimmy. if both their frequencies coincide,
    it's a real squirrelly ride.

  14. jim beam said:

    tension does not affect elasticity.


    Only when the spokes go slack...

  15. Ron Ruff said:
    jim beam said:

    tension does not affect elasticity.


    Only when the spokes go slack...


    ok...

  16. "Mike Jacoubowsky" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:

    http://www.wheelbuilder.com/tips/Spokes.asp
    "As the number of spoke crossings increase the angle in which each spoke
    leaves the hub approaches 90o (tangential). Wheels with 3x or 4x lace
    patterns will usually transfer power more efficiently than those with 2x
    patterns. As the number of spoke crossings increase the length of each


    spoke

    Quoted message said:

    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which


    is

    Quoted message said:

    about 5%, actually contribute to a difference you can feel?

    #2: How does "lower lateral stiffness" improve cornering stability?

    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com

    You opened a can of worms. I've preferred 4x cross low flange for years
    because they are slightly "softer" riding. I have several identical wheel
    set the only difference is 3x Vs 4x. I can definitely tell the difference.

    The difference between 288mm to 302mm is 14mm which times 2 for each side
    of the wheel is 28mm which is almost 1 1/8" in spoke length. Longer spokes
    are going to make a slightly more flexible wheel.

    The experts will start quoting all of their engineering formulas which
    mostly apply to static rather than dynamic conditions. A there are so many
    variables that a bicycle wheel in use can be better compared to fluid
    dynamics.

    The only time I've felt any lateral stiffness issues has been on very fast
    descents on high mountain roads with wide sweeping bends at speeds over 40
    mph.

    Chas.

  17. "Mike Jacoubowsky" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:
    Quoted message said:
    Quoted message said:

    #2: How does "lower lateral stiffness" improve cornering stability?

    it doesn't actually say "it improves it", it says lateral stiffness is
    important, but doesn't state the sense. lateral stiffness /can/ be
    important if the rider jockeys or the frame is not very stiff


    torsionally

    Quoted message said:
    Quoted message said:

    [shimmy], and stiffer is better.

    i guess your objective in this post is to illustrate misinformation


    and/or

    Quoted message said:
    Quoted message said:

    ambiguity. if so, do you have a position on the subject or do you


    just

    Quoted message said:
    Quoted message said:

    want to stir the pot?

    No, my objective was to find out what people thought about the idea that
    too-much lateral stiffness is a bad thing. This is a new one to me. To


    the

    Quoted message said:

    best of my knowledge, people here and elsewhere have tended towards
    stiffer=stronger=better for most things having to do with wheels.
    Intuitively, I'd think that lateral stiffness would enhance cornering.


    But

    Quoted message said:

    re-reading the paragraph in question-

    "As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    - Perhaps I had it backward, and they're saying that lateral stiffness,


    not

    Quoted message said:

    lower lateral stiffness, is a good thing?

    I have my own opinions, but I learn a lot more when I listen to what


    other

    Quoted message said:

    people have to say about something than when I'm trying to defend


    myself.

    Quoted message said:


    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com

    Interesting approach. My preference is for smooth riding bikes that absorb
    road shock and vibration. I'm not making any suggestions for others just
    reporting my experiences. I enjoy riding old steel retro bikes.

    I like a bike with a frame that is laterally stiff across the bottom
    bracket and rear triangle areas so that when I'm honking out of the saddle
    the chain doesn't rub back and forth on the front derailleur and in worst
    cases of too much flex the gears shift by themselves.

    I've found that light gage rear spokes whether 3x or 4x feel laterally
    flexible when honking.

    I recently rode a friend's LeMond with 2x 24 spoke wheels. The rear end
    had a really responsive light, crisp feel that I've only ever felt on one
    other bike over the years. My friend doesn't like the ride of most of my
    bikes. He says that they feel too spongy.

    OT - This brings up the old discussion: a stiff bike is better because it
    more efficiently transfers the rider's energy Vs. a more comfortable bike
    is more efficient because its easier on the rider.

    I like my short wheelbase bikes for rides up to 40 miles or so because
    they are more responsive. My old long wheelbase bikes are more comfortable
    for longer rides.

    Chas.

  18. "jim beam" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:
    Ron Ruff said:
    Mike Jacoubowsky said:

    - Perhaps I had it backward, and they're saying that lateral


    stiffness, not

    Quoted message said:
    Quoted message said:
    Quoted message said:

    lower lateral stiffness, is a good thing?

    I think they are saying that there is no free lunch... ie high lateral
    stiffness is good for cornering, but bad for ride smoothness.
    Personally, I think they are both insignificant effects. What you want
    in a wheel is enough strength and durability so that the rim doesn't
    taco and the spokes don't break. These qualities are weakly correlated
    with stiffness. Maybe a wheel with poor lateral stiffness can induce
    shimmy, but I've not experienced this.


    it doesn't induce it, but it's part of the shimmy equation. torsional
    frame stiffness and [rear] wheel lateral stiffness both affect the
    harmonic frequency of the shimmy. if both their frequencies coincide,
    it's a real squirrelly ride.

    I haven't seen many shimmy problems recently but years ago found a
    correlation between really long stems (130mm - 140mm) and front end shimmy
    on long fast descents.

    Changing to a shorter stem usually fixed the problem for many riders. At
    that time fork and frame alignment weren't checked out very often. After I
    built a few frames, I started checking alignment on any bike that felt
    squirrelly.

    In 1978 a customer brought in a brand new Bob Jackson bike that he got
    from a MO house. It wanted to ride in circles to the right. I could
    visually see the rear triangle was tweaked. One chainstay was 1/2" shorter
    than the other and the rest of the frame including the forks were badly
    aligned - the paint job was beautiful though.

    I wonder if people with shimmy problems ever check their frame alignment.

    Chas.

  19. jim beam said:

    lateral stiffness is better for [reducing] shimmy and leads to a more
    "stable" feel. but it goes hand in hand with radial stiffness, and too
    much of that can be uncomfortable for the rider.

    The FEA in Jobst's book shows a nominal 0.15mm radial deflection with a
    nominal 50kg load. What's your number for "uncomfortable"?

  20. Mike Jacoubowsky said:

    http://www.wheelbuilder.com/tips/Spokes.asp
    "As the number of spoke crossings increase the angle in which each spoke
    leaves the hub approaches 90o (tangential). Wheels with 3x or 4x lace
    patterns will usually transfer power more efficiently than those with 2x
    patterns. As the number of spoke crossings increase the length of each spoke
    increases. Longer spokes are more flexible and contribute to decreased
    radial stiffness, which improves ride quality. Consequently wheels with
    more spoke crossings have lower lateral stiffness, which is important to
    cornering stability."

    #1: Does a difference in spoke length from, say, 288mm to 302mm, which is
    about 5%, actually contribute to a difference you can feel?

    #2: How does "lower lateral stiffness" improve cornering stability?

    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com

    I think they're trying to invent a trade-off between "comfort" and
    "performance" -- adds a certain "cachet" to the wheel selection process,
    but unfortunately it's all BS -- creative marketing for a 100 year old
    product.

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