rebuild wheel or not?

Discussion in 'Cycling Equipment' started by Mark Runacres, Jul 30, 2004.

  1. I have a set of wheels that came with my bike when I bought it: Campagnolo
    Daytona hubs, Mavic Open Pro rims and 32 flat (aero) DT Swiss spokes. The
    rear wheel is laced three-cross on the drive side, radial on the non-drive
    side. After 6000 km without problems, I broke two spokes of the rear wheel
    over the last few hundred kms. I don't trust these wheels. Should I
    1. just throw away the wheels ?
    2. have them rebuilt in a more sensible pattern, using the same hub and rim,
    but different spokes? I know one isn't suppose to lace the same hub in
    different patterns, but is this really a problem after 6000km, if I
    inspect the hubs for cracks, from time to time?
    3. Try to stress-relieve the wheels and hope that fixes the problem?

    I am assuming I can continue to use the (radially spoked) front wheel.
    Thanks in advance for your advice.
     
    Tags:


  2. Certainly do not throw the wheels away, unless you're so rich you can
    afford it!

    You didn't mention how heavy or strong you are, but this might be the
    problem. Also, wheels laced like this are normally designed for time
    trials, which usually do not involve any realy hard pedalling, as would
    be encountered in sprinting or hill climbing.

    Have a competent wheel builder look at them, if they were improperly
    built he may be able to fix them. If they are simply not strong enough
    for your weight, strength or use, he can rebuild or replace as necessary
    to better suit you and your needs.

    - -

    "May you have the wind at your back.
    And a really low gear for the hills!"

    Chris Zacho ~ "Your Friendly Neighborhood Wheelman"

    Chris'Z Corner
    http://www.geocities.com/czcorner
     
  3. mark-<< Campagnolo
    Daytona hubs, Mavic Open Pro >><BR><BR>
    << 2. have them rebuilt in a more sensible pattern, using the same hub and rim,
    but different spokes? >><BR><BR>

    If you are breaking spokes it may be due to a 'deformed' or otherwise bent rim
    that is causing a place of lower than optimum tension. Bebuild with a new rim,
    14/15 spokes.

    You can try to remove all tension and re-do it all, with stress relieving and
    attempting to get the tension as equal as possible.

    Peter Chisholm
    Vecchio's Bicicletteria
    1833 Pearl St.
    Boulder, CO, 80302
    (303)440-3535
    http://www.vecchios.com
    "Ruote convenzionali costruite eccezionalmente bene"
     
  4. dianne_1234

    dianne_1234 Guest

    On 30 Jul 2004 08:40:36 -0700, [email protected] (Mark Runacres)
    wrote:

    >I have a set of wheels that came with my bike when I bought it: Campagnolo
    >Daytona hubs, Mavic Open Pro rims and 32 flat (aero) DT Swiss spokes. The
    >rear wheel is laced three-cross on the drive side, radial on the non-drive
    >side. After 6000 km without problems, I broke two spokes of the rear wheel
    >over the last few hundred kms. I don't trust these wheels. Should I
    >1. just throw away the wheels ?
    >2. have them rebuilt in a more sensible pattern, using the same hub and rim,
    >but different spokes? I know one isn't suppose to lace the same hub in
    >different patterns, but is this really a problem after 6000km, if I
    >inspect the hubs for cracks, from time to time?
    >3. Try to stress-relieve the wheels and hope that fixes the problem?
    >
    >I am assuming I can continue to use the (radially spoked) front wheel.
    >Thanks in advance for your advice.


    With good quality hubs and spokes like yours, broken spokes are most
    often caused by the builder's failure to stress relieve them.

    The fact that your spokes are bladed means it might have been
    uncomfortable to stress relieve them.

    I'd suggest wearing thick, padded leather gloves to stress relieve the
    spokes. Squeeze really hard. Try to break any other spokes that are
    about to break.

    Then re-tension, true, round and dish, and as Peter says, "go ride".
     
  5. jim beam

    jim beam Guest

    Mark Runacres wrote:
    > I have a set of wheels that came with my bike when I bought it: Campagnolo
    > Daytona hubs, Mavic Open Pro rims and 32 flat (aero) DT Swiss spokes. The
    > rear wheel is laced three-cross on the drive side, radial on the non-drive
    > side. After 6000 km without problems, I broke two spokes of the rear wheel
    > over the last few hundred kms. I don't trust these wheels. Should I
    > 1. just throw away the wheels ?


    no.

    > 2. have them rebuilt in a more sensible pattern, using the same hub and rim,
    > but different spokes? I know one isn't suppose to lace the same hub in
    > different patterns, but is this really a problem after 6000km, if I
    > inspect the hubs for cracks, from time to time?


    respokeing crossed to another crossed pattern is ok, but respoking
    radial to crossed exerts stress on the part of the hub hole that was
    notched in exactly the right orientation for fatigue. i guess if you
    inspect regularly, it'll be ok, but from a purist viewpoint, it's a bad
    plan.

    > 3. Try to stress-relieve the wheels and hope that fixes the problem?


    well, you don't say /which/ spokes broke. drive side or non-drive side?
    were the wheels tensioned correctly? i personally see no
    metallurgical benefit to what's termed "stress relief" in this
    application, but it definitely helps make sure spokes are bedded in to
    hubs & rims, so it's a good thing to do.

    >
    > I am assuming I can continue to use the (radially spoked) front wheel.
    > Thanks in advance for your advice.


    you may also want to consider a different spoke. d.t. don't publish
    fatigue ratings for their products, but sapim do. that in itself is not
    convincing, but to my way of thinking, it indicates greater confidence
    in what they do.
     
  6. On Fri, 30 Jul 2004 19:16:15 -0700, jim beam wrote:

    > Mark Runacres wrote:
    >> I have a set of wheels that came with my bike when I bought it: Campagnolo
    >> Daytona hubs, Mavic Open Pro rims and 32 flat (aero) DT Swiss spokes. The
    >> rear wheel is laced three-cross on the drive side, radial on the non-drive
    >> side. After 6000 km without problems, I broke two spokes of the rear wheel
    >> over the last few hundred kms. I don't trust these wheels. Should I
    >> 1. just throw away the wheels ?


    Send the hubs to me....

    >> 2. have them rebuilt in a more sensible pattern, using the same hub and rim,
    >> but different spokes? I know one isn't suppose to lace the same hub in
    >> different patterns, but is this really a problem after 6000km, if I
    >> inspect the hubs for cracks, from time to time?


    OK, the pattern is not _that_ unreasonable, so you can re-use it. If you
    want to do the left-side spokes with a semi-tangential pattern, it'll be
    all right. Most of the stresses are on the right-side flange, anyway. I
    would use 14/15 round spokes, though.

    >> 3. Try to stress-relieve the wheels and hope that fixes the problem?

    >
    > well, you don't say /which/ spokes broke. drive side or non-drive side?


    I bet it was the left side (also known as the contrary-to-drive-side, or
    whatever). Those are more likely to be exposed to cycles of complete
    de-tensioning, especially if the wheel did not have adequate tension to
    begin with, as is often the case. I'd probably replace the spokes if I
    were you, just because I don't trust bladed spokes as much as round ones.
    it's a good thing to do.

    --

    David L. Johnson

    __o | Become MicroSoft-free forever. Ask me how.
    _`\(,_ |
    (_)/ (_) |
     
  7. jim beam

    jim beam Guest

    David L. Johnson wrote:
    > On Fri, 30 Jul 2004 19:16:15 -0700, jim beam wrote:
    >
    >
    >>Mark Runacres wrote:
    >>
    >>>I have a set of wheels that came with my bike when I bought it: Campagnolo
    >>>Daytona hubs, Mavic Open Pro rims and 32 flat (aero) DT Swiss spokes. The
    >>>rear wheel is laced three-cross on the drive side, radial on the non-drive
    >>>side. After 6000 km without problems, I broke two spokes of the rear wheel
    >>>over the last few hundred kms. I don't trust these wheels. Should I
    >>>1. just throw away the wheels ?

    >
    >
    > Send the hubs to me....
    >
    >
    >>>2. have them rebuilt in a more sensible pattern, using the same hub and rim,
    >>>but different spokes? I know one isn't suppose to lace the same hub in
    >>>different patterns, but is this really a problem after 6000km, if I
    >>>inspect the hubs for cracks, from time to time?

    >
    >
    > OK, the pattern is not _that_ unreasonable, so you can re-use it. If you
    > want to do the left-side spokes with a semi-tangential pattern, it'll be
    > all right. Most of the stresses are on the right-side flange, anyway. I
    > would use 14/15 round spokes, though.
    >
    >
    >>>3. Try to stress-relieve the wheels and hope that fixes the problem?

    >>
    >>well, you don't say /which/ spokes broke. drive side or non-drive side?

    >
    >
    > I bet it was the left side (also known as the contrary-to-drive-side, or
    > whatever). Those are more likely to be exposed to cycles of complete
    > de-tensioning, especially if the wheel did not have adequate tension to
    > begin with, as is often the case. I'd probably replace the spokes if I
    > were you, just because I don't trust bladed spokes as much as round ones.


    why? if sapim's spoke fatigue tales are anything to go by, their bladed
    spokes have a much better fatigue life than their round ones.

    > it's a good thing to do.
    >
     
  8. On Fri, 30 Jul 2004 20:21:16 -0700, jim beam
    <[email protected]> wrote:

    >
    >David L. Johnson wrote:


    [snip]

    >> I don't trust bladed spokes as much as round ones.

    >
    >why? if sapim's spoke fatigue tales are anything to go by, their bladed
    >spokes have a much better fatigue life than their round ones.


    Dear Jim,

    I'm wondering why bladed spokes would resist fatigue better
    than round ones. Do you have a link to the Sapim stuff?

    Don't both kinds of spokes have roughly similar ends, where
    most failures occur?

    Do the bladed spokes benefit from work-hardening?

    Are they--the proper word escapes me--stretchier in the
    fashion of double-butted spokes being stretchier than
    straight spokes?

    And if they are indeed more fatigue-resistant, are bladed
    spokes usually subjected to the spoke-squeezing process so
    often mentioned on rec.bicycles.tech? (Somehow I have
    trouble imagining squeezing bladed spokes together, even
    with gloves, but maybe it's not as bad as I think.)

    Carl Fogel
     
  9. On Fri, 30 Jul 2004 22:48:46 -0400, "David L. Johnson"
    <[email protected]> wrote:

    [snip broken-spoke details]

    >I bet it was the left side (also known as the contrary-to-drive-side, or
    >whatever). Those are more likely to be exposed to cycles of complete
    >de-tensioning, especially if the wheel did not have adequate tension to
    >begin with, as is often the case.


    Dear David,

    Do you find most broken spokes on the non-drive side?

    My impression (and experience) is that spokes break most
    often at the elbow on the drive side.

    As I understand it, the spokes on both sides de-tension
    roughly the same amount as they pass under the axle, but the
    drive-side ones break more often because they are under
    greater tension to make up for their shallow angle to the
    rim.

    Carl Fogel
     
  10. jim beam

    jim beam Guest

    [email protected] wrote:
    > On Fri, 30 Jul 2004 20:21:16 -0700, jim beam
    > <[email protected]> wrote:
    >
    >
    >>David L. Johnson wrote:

    >
    >
    > [snip]
    >
    >
    >>> I don't trust bladed spokes as much as round ones.

    >>
    >>why? if sapim's spoke fatigue tales are anything to go by, their bladed
    >>spokes have a much better fatigue life than their round ones.

    >
    >
    > Dear Jim,
    >
    > I'm wondering why bladed spokes would resist fatigue better
    > than round ones. Do you have a link to the Sapim stuff?


    http://www.seetool.be/sites/sapim/index.php?st=products&sub=spokes&detail=fatiguetest

    to be honest, i don't know for sure why that would be, but i'd guess
    it's something to do with the bending component present at the spoke
    elbow. a bladed spoke would be able to exert less bend in the plane of
    the blade compared with a round spoke.

    >
    > Don't both kinds of spokes have roughly similar ends, where
    > most failures occur?


    yes. but i have noticed for example that the surface finish on sapim's
    unbutted spokes is not as good as their butted ones, so maybe they also
    finish their bladed spokes even more carefully. they certainly should
    for the price they charge!

    >
    > Do the bladed spokes benefit from work-hardening?


    no more than ordinary spokes benefit from normal butting.

    >
    > Are they--the proper word escapes me--stretchier in the
    > fashion of double-butted spokes being stretchier than
    > straight spokes?


    if the material in the bladed section is less, yes. it's simply a
    function of cross section area. usine the formula for an elipse is
    probably a good approximation.

    >
    > And if they are indeed more fatigue-resistant, are bladed
    > spokes usually subjected to the spoke-squeezing process so
    > often mentioned on rec.bicycles.tech? (Somehow I have
    > trouble imagining squeezing bladed spokes together, even
    > with gloves, but maybe it's not as bad as I think.)


    mavic recommend a different method: pressing the hub axle hard against
    a flat surface while pressing on the rim. it achieves over-tension
    therefore bedding in the spokes, but does not mean touching the spokes.
    it seems to work quite well if repeating until the wheel stays in true
    is any indication - just as well as spoke squeezing at any rate.

    >
    > Carl Fogel
     
  11. On Fri, 30 Jul 2004 23:26:32 -0600, carlfogel wrote:

    > On Fri, 30 Jul 2004 22:48:46 -0400, "David L. Johnson"
    > <[email protected]> wrote:
    >
    > [snip broken-spoke details]
    >
    >>I bet it was the left side (also known as the contrary-to-drive-side, or
    >>whatever). Those are more likely to be exposed to cycles of complete
    >>de-tensioning, especially if the wheel did not have adequate tension to
    >>begin with, as is often the case.

    >
    > Dear David,
    >
    > Do you find most broken spokes on the non-drive side?
    >
    > My impression (and experience) is that spokes break most
    > often at the elbow on the drive side.


    Depends on the cause. This was a wheel that had few miles on it, and if
    spokes are breaking already I would bet it's from complete de-tensioning,
    which is more likely on left-side spokes since they have less tension to
    begin with. This is also more likely with wheels that are too loose to
    begin with.

    --

    David L. Johnson

    __o | The lottery is a tax on those who fail to understand
    _`\(,_ | mathematics.
    (_)/ (_) |
     
  12. ZeeExSixAre

    ZeeExSixAre Guest

    > trust these wheels. Should I
    > 1. just throw away the wheels ?


    I will pay shipping to have them sent to me... I will dispose of them
    properly, as the grease inside is highly toxic and cannot be simply thrown
    away in any dump.

    --
    Phil, Squid-in-Training
     
  13. Robert

    Robert Guest

    jim beam wrote:
    > [email protected] wrote:
    >
    >> On Fri, 30 Jul 2004 20:21:16 -0700, jim beam
    >> <[email protected]> wrote:
    >>
    >>
    >>> David L. Johnson wrote:

    >>
    >>
    >>
    >> [snip]
    >>
    >>
    >>>> I don't trust bladed spokes as much as round ones.
    >>>
    >>>
    >>> why? if sapim's spoke fatigue tales are anything to go by, their
    >>> bladed spokes have a much better fatigue life than their round ones.

    >>
    >>
    >>
    >> Dear Jim,
    >>
    >> I'm wondering why bladed spokes would resist fatigue better
    >> than round ones. Do you have a link to the Sapim stuff?

    >
    >
    > http://www.seetool.be/sites/sapim/index.php?st=products&sub=spokes&detail=fatiguetest
    >
    >
    > to be honest, i don't know for sure why that would be, but i'd guess
    > it's something to do with the bending component present at the spoke
    > elbow. a bladed spoke would be able to exert less bend in the plane of
    > the blade compared with a round spoke.
    >
    >>
    >> Don't both kinds of spokes have roughly similar ends, where
    >> most failures occur?

    >
    >
    > yes. but i have noticed for example that the surface finish on sapim's
    > unbutted spokes is not as good as their butted ones, so maybe they also
    > finish their bladed spokes even more carefully. they certainly should
    > for the price they charge!
    >
    >>
    >> Do the bladed spokes benefit from work-hardening?

    >
    >
    > no more than ordinary spokes benefit from normal butting.
    >
    >>
    >> Are they--the proper word escapes me--stretchier in the
    >> fashion of double-butted spokes being stretchier than
    >> straight spokes?

    >
    >
    > if the material in the bladed section is less, yes. it's simply a
    > function of cross section area. usine the formula for an elipse is
    > probably a good approximation.
    >
    >>
    >> And if they are indeed more fatigue-resistant, are bladed
    >> spokes usually subjected to the spoke-squeezing process so
    >> often mentioned on rec.bicycles.tech? (Somehow I have
    >> trouble imagining squeezing bladed spokes together, even
    >> with gloves, but maybe it's not as bad as I think.)


    There are different ways of pulling on the spokes. One is pinching the
    pairs together, in the same plane as the one in which the lie; the other
    is to push or pull each one at right angles to the plane. With bladed
    spokes this is more comfortable to the hands. What's important is that
    each spoke is given a temporary and significant increase in tension . . .
    >
    >
    > mavic recommend a different method: pressing the hub axle hard against
    > a flat surface while pressing on the rim. it achieves over-tension
    > therefore bedding in the spokes, but does not mean touching the spokes.
    > it seems to work quite well if repeating until the wheel stays in true
    > is any indication - just as well as spoke squeezing at any rate.
    >

    Agree that this works very well, too.

    [also referring to other postings in this thread] Having built with
    straight-gauge, butted, and bladed, I don't understand the hullaballoo
    about the durability of bladed vs. straight, or whether tension ratings
    are published on the web site for Sapim, DT, or whoever. The bladed ones
    I use are DT Aero Speed. At both elbow and threaded ends, they're round
    in cross-section, just as any "normal" spokes are. With a cross-section
    of 2,3 * 1,2 mm (IIRC), they don't require that the hub holes are filed.
    They're also flat enough so that the user *thinks* that he/she will ride
    faster with them. A good buy at one USD dollar/spoke here in Europe.

    The wheelset I've built have very high spoke tension, using the DT Aero
    Speed spoke. Performed usual stress-relieving measures in all cases.
    Have ridden on all types of roads and find them to be very durable so
    far. OK - the jury's out on actual endurance because these wheels have
    not quite gone 3000 km. But I foresee no problems. I've not had to
    adjust the true/roundness since a trivial touch-up after the first ride.

    (for those wondering: other gear on this wheelset is: brass nipples,
    Mavic OP Ceramic, Campag Record 32h, Veloflex Master, all supporting
    rider (me) weighing 74 kg (160 lb) who is decent sprinter. Lacing is x2
    on front (290 mm), x3 DS (293 mm), x1 NDS (284 mm). Gives a good
    wheelset for long rides and impressing friends and neighbours).

    YMMV.

    /Robert
     
  14. jim beam wrote:

    > mavic recommend a different method: pressing the hub axle hard against a
    > flat surface while pressing on the rim. it achieves over-tension
    > therefore bedding in the spokes, but does not mean touching the
    > spokes.


    FWIW, I tacoed a (dished rear) wheel doing this once. How do they suggest
    holding the rim while doing this? You need to apply many times the force
    that squeezing opposing pairs of spokes by hand requires, in order to
    overtension the spokes an equal amount.

    Is there some reason touching the spokes is to be avoided?

    --
    Benjamin Lewis

    A small, but vocal, contingent even argues that tin is superior, but they
    are held by most to be the lunatic fringe of Foil Deflector Beanie science.
     
  15. [email protected] (Chris Zacho "The Wheelman") wrote in message news:<[email protected]>...

    >
    > You didn't mention how heavy or strong you are, but this might be the
    > problem. Also, wheels laced like this are normally designed for time
    > trials, which usually do not involve any realy hard pedalling, as would
    > be encountered in sprinting or hill climbing.
    >

    I am rather light (65 kg, 145 lbs) and not extremely strong. Just a
    trained recreational cyclist.
     
  16. [email protected] (Qui si parla Campagnolo ) wrote in message news:<[email protected]>...
    > mark-<< Campagnolo
    > Daytona hubs, Mavic Open Pro >><BR><BR>
    > << 2. have them rebuilt in a more sensible pattern, using the same hub and rim,
    > but different spokes? >><BR><BR>
    >
    > If you are breaking spokes it may be due to a 'deformed' or otherwise bent rim
    > that is causing a place of lower than optimum tension. Bebuild with a new rim,
    > 14/15 spokes.
    >

    The rim looks fine. The wheel was perfectly true before I broke the
    first spoke and is true again now. It was very much out of true after
    I broke the spoke, obviously. Can this damage the rim in a way that is
    not obvious to see?

    If I use a new rim, on the same hubs, should I keep the spoke pattern?
     
  17. "David L. Johnson" <[email protected]> wrote in message news:<[email protected]>...
    > On Fri, 30 Jul 2004 19:16:15 -0700, jim beam wrote:
    >


    > > well, you don't say /which/ spokes broke. drive side or non-drive side?

    >
    > I bet it was the left side (also known as the contrary-to-drive-side, or
    > whatever). Those are more likely to be exposed to cycles of complete
    > de-tensioning, especially if the wheel did not have adequate tension to
    > begin with, as is often the case. I'd probably replace the spokes if I
    > were you, just because I don't trust bladed spokes as much as round ones.
    > it's a good thing to do.


    No, it was the right (drive) side, both times. The second spoke broke
    near the nipple, where the thread starts.
     
  18. jim beam

    jim beam Guest

    Benjamin Lewis wrote:
    > jim beam wrote:
    >
    >
    >>mavic recommend a different method: pressing the hub axle hard against a
    >>flat surface while pressing on the rim. it achieves over-tension
    >>therefore bedding in the spokes, but does not mean touching the
    >>spokes.

    >
    >
    > FWIW, I tacoed a (dished rear) wheel doing this once.


    what was the tension? rims do this anyway if the tension is too high.

    > How do they suggest
    > holding the rim while doing this?


    "put the hub axle of the wheel on a wooden block and push on opposite
    sides of the rim with your hands" there's a pic too, but i can't link
    to their web page any more - it's password protected.

    > You need to apply many times the force
    > that squeezing opposing pairs of spokes by hand requires, in order to
    > overtension the spokes an equal amount.


    doesn't matter as long as the wheel experinces the same effect.

    >
    > Is there some reason touching the spokes is to be avoided?


    no, but it's uncomfortable doing "spoke squeeze" with bladed spokes, a
    point raised earlier in this thread.
     
  19. jim beam

    jim beam Guest

    Mark Runacres wrote:
    > "David L. Johnson" <[email protected]> wrote in message news:<[email protected]>...
    >
    >>On Fri, 30 Jul 2004 19:16:15 -0700, jim beam wrote:
    >>

    >
    >
    >>>well, you don't say /which/ spokes broke. drive side or non-drive side?

    >>
    >>I bet it was the left side (also known as the contrary-to-drive-side, or
    >>whatever). Those are more likely to be exposed to cycles of complete
    >>de-tensioning, especially if the wheel did not have adequate tension to
    >>begin with, as is often the case. I'd probably replace the spokes if I
    >>were you, just because I don't trust bladed spokes as much as round ones.
    >>it's a good thing to do.

    >
    >
    > No, it was the right (drive) side, both times. The second spoke broke
    > near the nipple, where the thread starts.


    ok. the second failure, while it does happen, is comparatively rare.
    it could be because the spokes are fractionally too long and there is a
    thread binding problem where the nipple has run out of thread. check to
    see if the spokes are sticking out of the nipple head at all - they
    should be flush with the bottom of the drive slot.

    other than that, just replace and make sure the wheel is built properly,
    tensioned to spec & tensioned evenly. the two failures are almost
    certainly unrelated.
     
  20. jim beam wrote:

    > Benjamin Lewis wrote:
    >> jim beam wrote:
    >>
    >>> mavic recommend a different method: pressing the hub axle hard against
    >>> a flat surface while pressing on the rim. it achieves over-tension
    >>> therefore bedding in the spokes, but does not mean touching the spokes.

    >> FWIW, I tacoed a (dished rear) wheel doing this once.

    >
    > what was the tension? rims do this anyway if the tension is too high.


    I don't know, but it was well under Jobst's "maximum compressive strength
    of rim".

    I rebuilt the wheel, and have ridden several hundred kms on it since then
    with no problems.

    In order to apply the same force per spoke as I do when stress relieving by
    squeezing, I'd probably have to stand on the wheel, and maybe jump a bit.

    >> You need to apply many times the force
    >> that squeezing opposing pairs of spokes by hand requires, in order to
    >> overtension the spokes an equal amount.

    >
    > doesn't matter as long as the wheel experinces the same effect.


    In my case it didn't; the rim tacoed.

    --
    Benjamin Lewis

    Seeing is deceiving. It's eating that's believing.
    -- James Thurber
     
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