Pulling/trailing spokes run along inside or outside of flange?

Discussion in 'Cycling Equipment' started by [email protected], Dec 25, 2005.

  1. Hello,

    When building wheels I've use the lacing method which runs the
    pulling/trailing spokes along the inside of the hub flange. A few of
    the much more experienced mechanics at the shop I have told me that
    this is the wrong, but I am unsatisfied with their explainations.

    I double-checked The Bicycle Wheel and Sheldon Brown's site and found
    that both lacing instructions result in a wheel with pulling spokes
    running along the inside of the flange. Sheldon Brown cites a few
    reasons for this orientation--
    http://www.sheldonbrown.com/wheelbuild.html#side

    The only explaination provided by my co-workers that resembled sense
    was that when the pulling spokes run along the outside of the flange
    the flange spacing is effectively wider, making the pulling spokes
    stronger. It is my understanding that a wider flange spacing makes a
    wheel laterally and radially stronger, but that it doesn't increase
    torque transmission to the rim. In fact, it seems to me that it would
    decrease (however slightly) the pulling spokes ability to "pull".

    Can anyone explain what, if any, effect on torque would be produced by
    running the pulling spokes along the inside vs. outside of the flange?
    The people telling me to run them along the outside have about a decade
    more wrench experience than I, so I need to properly explain why they
    should be run along the inside of the flange if I am going to continue
    to do so at the shop.

    Thanks, and Merry Christmas,
    Anthony King
     
    Tags:


  2. Anthony King writes:

    > When building wheels I've use the lacing method which runs the
    > pulling/trailing spokes along the inside of the hub flange. A few
    > of the much more experienced mechanics at the shop I have told me
    > that this is the wrong, but I am unsatisfied with their
    > explanations.


    > I double-checked The Bicycle Wheel and Sheldon Brown's site and
    > found that both lacing instructions result in a wheel with pulling
    > spokes running along the inside of the flange. Sheldon Brown cites
    > a few reasons for this orientation--


    http://www.sheldonbrown.com/wheelbuild.html#side

    > The only explanation provided by my co-workers that resembled sense
    > was that when the pulling spokes run along the outside of the flange
    > the flange spacing is effectively wider, making the pulling spokes
    > stronger. It is my understanding that a wider flange spacing makes
    > a wheel laterally and radially stronger, but that it doesn't
    > increase torque transmission to the rim. In fact, it seems to me
    > that it would decrease (however slightly) the pulling spokes ability
    > to "pull".


    Well that doesn't hold water if you interleave spokes, because when
    interlaced, they take an average approach angle that bisects the flange
    width. Besides, how much do these folks believe the angular difference
    is?

    > Can anyone explain what, if any, effect on torque would be produced
    > by running the pulling spokes along the inside vs. outside of the
    > flange? The people telling me to run them along the outside have
    > about a decade more wrench experience than I, so I need to properly
    > explain why they should be run along the inside of the flange if I
    > am going to continue to do so at the shop.


    You seem to have "the Bicycle Wheel" at hand and it shows how small
    torque loads on spokes are. Remember that all external loads shown
    are the same, so the torque load is the same as the vertical load on
    the wheel for easy comparison.

    Jobst Brandt
     
  3. Mark Janeba

    Mark Janeba Guest

    [email protected] wrote:
    > Hello,
    >
    > When building wheels I've use the lacing method which runs the
    > pulling/trailing spokes along the inside of the hub flange. A few of
    > the much more experienced mechanics at the shop I have told me that
    > this is the wrong, but I am unsatisfied with their explainations.
    >
    > I double-checked The Bicycle Wheel and Sheldon Brown's site and found
    > that both lacing instructions result in a wheel with pulling spokes
    > running along the inside of the flange. Sheldon Brown cites a few
    > reasons for this orientation--
    > http://www.sheldonbrown.com/wheelbuild.html#side


    Sheldon's reason #2 makes a LOT of sense, and it's the only reason I
    need when building wheels. ("If the chain should overshoot the inner
    sprocket due to the derailer being mis-adjusted or bent, it is likely to
    get more seriously jammed between the spokes and the freewheel if the
    spokes slant so as to wedge the chain inward under load.")

    I suspect all *other* advantages of one side over the other are
    negligible for most of us most of the time.

    I assume most of us will drop the chain between the cogs and spokes
    rarely if ever, but doing it just once will persuade you. It can be a
    bear pulling the chain out of there when the spokes are angled to wedge
    it in; what's worse, I think the spokes get "chewed" more in this situation.

    Mark "Been there, done that" Janeba

    (and a happy holiday to all)
     
  4. A Muzi

    A Muzi Guest

    [email protected] wrote:
    > Hello,
    >
    > When building wheels I've use the lacing method which runs the
    > pulling/trailing spokes along the inside of the hub flange. A few of
    > the much more experienced mechanics at the shop I have told me that
    > this is the wrong, but I am unsatisfied with their explainations.
    >
    > I double-checked The Bicycle Wheel and Sheldon Brown's site and found
    > that both lacing instructions result in a wheel with pulling spokes
    > running along the inside of the flange. Sheldon Brown cites a few
    > reasons for this orientation--
    > http://www.sheldonbrown.com/wheelbuild.html#side
    >
    > The only explaination provided by my co-workers that resembled sense
    > was that when the pulling spokes run along the outside of the flange
    > the flange spacing is effectively wider, making the pulling spokes
    > stronger. It is my understanding that a wider flange spacing makes a
    > wheel laterally and radially stronger, but that it doesn't increase
    > torque transmission to the rim. In fact, it seems to me that it would
    > decrease (however slightly) the pulling spokes ability to "pull".
    >
    > Can anyone explain what, if any, effect on torque would be produced by
    > running the pulling spokes along the inside vs. outside of the flange?
    > The people telling me to run them along the outside have about a decade
    > more wrench experience than I, so I need to properly explain why they
    > should be run along the inside of the flange if I am going to continue
    > to do so at the shop.


    Even people who are picky about nits ( me) admit this can be
    argued either way.

    With 'pulling' spokes on the inside there is less lash under
    extreme side loads - the spoke can't straighten much if it
    is already straight. OTOH, building in the inverse means an
    errant rear changer will be less likely to mate with a
    spoke. Neither scenario is common and the effect in each
    case is minimal, so it doesn't matter.

    I build 'pulling' spokes inside but I don't believe the
    other way is wrong.

    Now if you want to split hairs, I build fronts such that
    left side innies go clockwise and right side innies go
    counterclockwise. You'll get an argument from other
    builders that a front ought to be built like a rear instead.
    ( all innies going the same way)

    It truly doesn't make any difference I can see. The
    discussion is only a shade past rim label/hub label
    position and all that drivel.


    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971
     
  5. Werehatrack

    Werehatrack Guest

    On 25 Dec 2005 12:43:54 -0800, "[email protected]"
    <[email protected]> wrote:

    >Hello,
    >
    >When building wheels I've use the lacing method which runs the
    >pulling/trailing spokes along the inside of the hub flange. A few of
    >the much more experienced mechanics at the shop I have told me that
    >this is the wrong, but I am unsatisfied with their explainations.


    Properly, IMO.

    >I double-checked The Bicycle Wheel and Sheldon Brown's site and found
    >that both lacing instructions result in a wheel with pulling spokes
    >running along the inside of the flange. Sheldon Brown cites a few
    >reasons for this orientation--
    >http://www.sheldonbrown.com/wheelbuild.html#side
    >
    >The only explaination provided by my co-workers that resembled sense
    >was that when the pulling spokes run along the outside of the flange
    >the flange spacing is effectively wider, making the pulling spokes
    >stronger. It is my understanding that a wider flange spacing makes a
    >wheel laterally and radially stronger, but that it doesn't increase
    >torque transmission to the rim. In fact, it seems to me that it would
    >decrease (however slightly) the pulling spokes ability to "pull".


    If this angle mattered at all, which I can't say whether it does, the
    cross pattern would have more to do with it than the lateral angle,
    since the degree to which the spoke is approaching the hub flange
    tangentially would seem to be the important consideration.

    Still, there's nothing to support any contention that the trailing
    spokes should be head-in as far as I can see. Running the trailing
    spokes head-out (as you do, and as is recommended elsewhere as you
    discovered) puts slightly less lateral stress on the flange under
    acceleration, however, so that's the way I would arrange them...and
    from what I just saw on the bikes in the stable, somebody must agree
    with that policy even if they have different reasons for doing so.

    >Can anyone explain what, if any, effect on torque would be produced by
    >running the pulling spokes along the inside vs. outside of the flange?
    >The people telling me to run them along the outside have about a decade
    >more wrench experience than I, so I need to properly explain why they
    >should be run along the inside of the flange if I am going to continue
    >to do so at the shop.


    My advice in this circumstance: Lace *your* wheels the way *you*
    prefer, and lace the *shop's* wheels the way that the shop management
    is paying you to, if they have a policy about it, unless explicitly
    instructed to do otherwise by a wheel's owner.

    --
    Typoes are a feature, not a bug.
    Some gardening required to reply via email.
    Words processed in a facility that contains nuts.
     
  6. Werehatrack

    Werehatrack Guest

    On 25 Dec 2005 12:43:54 -0800, "[email protected]"
    <[email protected]> wrote:

    >Hello,
    >
    >When building wheels I've use the lacing method which runs the
    >pulling/trailing spokes along the inside of the hub flange. A few of
    >the much more experienced mechanics at the shop I have told me that
    >this is the wrong, but I am unsatisfied with their explainations.


    Properly, IMO.

    >I double-checked The Bicycle Wheel and Sheldon Brown's site and found
    >that both lacing instructions result in a wheel with pulling spokes
    >running along the inside of the flange. Sheldon Brown cites a few
    >reasons for this orientation--
    >http://www.sheldonbrown.com/wheelbuild.html#side
    >
    >The only explaination provided by my co-workers that resembled sense
    >was that when the pulling spokes run along the outside of the flange
    >the flange spacing is effectively wider, making the pulling spokes
    >stronger. It is my understanding that a wider flange spacing makes a
    >wheel laterally and radially stronger, but that it doesn't increase
    >torque transmission to the rim. In fact, it seems to me that it would
    >decrease (however slightly) the pulling spokes ability to "pull".


    If this angle matters at all, the cross pattern has far more to do
    with it than the lateral angle, since the degree to which the spoke is
    approaching the hub flange tangentially is the important
    consideration. The only difference head-in vs head-out appears to
    make in that area is in the angle that the load is applied to the
    flange in the lateral direction, and that's not at the same level of
    importance as the tangentiality. Radial lacing places the load across
    the smallest cross-section of the flange, cross lacing angles it so
    that there's more flange material bearing the load. Head-in vs
    head-out won't make a difference in that, so the loading argument
    doesn't apply in the same manner in the in/out discussion. Looking at
    the real difference, the lateral angular change between head-in and
    head-out is so slight, and the acceleration vectors are so small in
    that regard that the lateral force generated by the very slight
    angular difference between head-in and head-out isn't enough to be
    critical.

    The observations elswhere about the potential for chain jam
    escalation, which is a real-world issue that is easy to see, look like
    the real trumps in this discussion.

    In total, there's nothing persuasive to support any contention that
    the trailing spokes should be head-in as far as I can see. Running
    the trailing spokes head-out (as you and I do, and as is recommended
    elsewhere as you discovered) may put very slightly less lateral stress
    on the flange under acceleration, but even that's not an important
    consideration by comparison to others...though it still supports
    head-out for the trailing spokes, not head-in, in my opinion.

    Whatever the rationale that is driving it, from a quick survey of the
    bikes in the stable, it appears that the majority opinion favors the
    trailing-head-out approach, as not one of the wheels here is built
    with the trailing spokes head-in on the rear.

    >Can anyone explain what, if any, effect on torque would be produced by
    >running the pulling spokes along the inside vs. outside of the flange?


    There isn't any difference in torque transmission from the hub to the
    rim. The microscopic difference in lateral loading of the hub flange
    (if measurable) will have no effect.

    >The people telling me to run them along the outside have about a decade
    >more wrench experience than I, so I need to properly explain why they
    >should be run along the inside of the flange if I am going to continue
    >to do so at the shop.


    My advice in this circumstance: Lace *your* wheels the way *you*
    prefer, and lace the *shop's* wheels the way that the shop management
    is paying you to, if they have a policy about it, unless explicitly
    instructed to do otherwise by a wheel's owner.

    Much of the real world operates on superstition rather than knowledge;
    where it matters, when you can differentiate the two, it's worth
    standing up for the knowledge-driven viewpoint in my opinion. Where
    it doesn't matter, and in particular where it's somebody else's
    reputation that will suffer for the choice, the decision about whether
    to remain silent or to try to educate the misinformed is one that must
    be made by the person on the spot. I believe that your dilemma falls
    into this category. Do as you feel the situation merits.


    --
    Typoes are a feature, not a bug.
    Some gardening required to reply via email.
    Words processed in a facility that contains nuts.
     
  7. [email protected] wrote:
    > Hello,
    >
    > When building wheels I've use the lacing method which runs the
    > pulling/trailing spokes along the inside of the hub flange. A few of
    > the much more experienced mechanics at the shop I have told me that
    > this is the wrong, but I am unsatisfied with their explainations.


    Not 'wrong', in practice, it just doesn't matter.
    >
    > I double-checked The Bicycle Wheel and Sheldon Brown's site and found
    > that both lacing instructions result in a wheel with pulling spokes
    > running along the inside of the flange. Sheldon Brown cites a few
    > reasons for this orientation--
    > http://www.sheldonbrown.com/wheelbuild.html#side
    >
    > The only explaination provided by my co-workers that resembled sense
    > was that when the pulling spokes run along the outside of the flange
    > the flange spacing is effectively wider, making the pulling spokes
    > stronger. It is my understanding that a wider flange spacing makes a
    > wheel laterally and radially stronger, but that it doesn't increase
    > torque transmission to the rim. In fact, it seems to me that it would
    > decrease (however slightly) the pulling spokes ability to "pull".
    >
    > Can anyone explain what, if any, effect on torque would be produced by
    > running the pulling spokes along the inside vs. outside of the flange?
    > The people telling me to run them along the outside have about a decade
    > more wrench experience than I, so I need to properly explain why they
    > should be run along the inside of the flange if I am going to continue
    > to do so at the shop.
    >
    > Thanks, and Merry Christmas,
    > Anthony King
     
  8. Mike Yankee

    Mike Yankee Guest

    >Sheldon's reason #2 makes a LOT of sense, and it's the only reason I need when building wheels. ("If the chain should overshoot the inner sprocket...

    Couldn't agree more, and I always lace my wheels that way. Here's a
    "true" story about wrong-way wheels, though: Two years ago I removed
    the original, shop-built rear wheel of my Merckx, which had remained
    absolutely true for 25,000+ miles without ever having to be touched, to
    put it on a "new" beater/rainbike I was building built up. Only then
    did I notice -- you guessed it -- the super-true rear had been laced
    the "wrong" way! Even now, with almost 28,000 miles on it, it's still
    as true as the day it was built, far and away the truest wheel I've
    ever owned.
     
  9. Werehatrack

    Werehatrack Guest

    On 26 Dec 2005 06:46:51 -0800, "Mike Yankee" <[email protected]>
    wrote:

    >>Sheldon's reason #2 makes a LOT of sense, and it's the only reason I need when building wheels. ("If the chain should overshoot the inner sprocket...

    >
    >Couldn't agree more, and I always lace my wheels that way. Here's a
    >"true" story about wrong-way wheels, though: Two years ago I removed
    >the original, shop-built rear wheel of my Merckx, which had remained
    >absolutely true for 25,000+ miles without ever having to be touched, to
    >put it on a "new" beater/rainbike I was building built up. Only then
    >did I notice -- you guessed it -- the super-true rear had been laced
    >the "wrong" way! Even now, with almost 28,000 miles on it, it's still
    >as true as the day it was built, far and away the truest wheel I've
    >ever owned.


    But I'd bet that lacing it the other way would have been just as
    effective in producing that result.
    --
    Typoes are a feature, not a bug.
    Some gardening required to reply via email.
    Words processed in a facility that contains nuts.
     
  10. Ron Ruff

    Ron Ruff Guest

    Mike Yankee wrote:
    > Even now, with almost 28,000 miles on it, it's still
    > as true as the day it was built, far and away the truest wheel I've
    > ever owned.


    Any particulars about your nice wheel... spokes, #, rim?
     
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