Shifting problem (record 10)

Discussion in 'Cycling Equipment' started by peterwright, Feb 17, 2004.

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  1. peterwright

    peterwright New Member

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    I am having a problem having rebuilt a cassette (12-25) after losing a spacer. The rear mech is adjusted correctly as far as I can see and engages all cogs correctly. When in the 21 however the chain jumps and skips constantly when under load (both big and small ring). It does not seem to jump cogs but just loses grip and regains it (at least that is what it feels like)

    The spacing looks correct and my other wheels work perfectly (11-23)

    Any help really appreciated.

    Thanks

    Peter
     
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  2. Kenny Lee

    Kenny Lee Guest

    peterwright wrote:

    > I am having a problem having rebuilt a cassette (12-25) after losing a spacer. The rear mech is
    > adjusted correctly as far as I can see and engages all cogs correctly. When in the 21 however the
    > chain jumps and skips constantly when under load (both big and small ring). It does not seem to
    > jump cogs but just loses grip and regains it (at least that is what it feels like)
    >
    > The spacing looks correct and my other wheels work perfectly (11-23)
    >
    > Any help really appreciated.
    >
    > Thanks
    >
    > Peter

    Sounds like when you reassembled your cassette you got a couple of the spacers back in the wrong
    order. I remember doing this and got the results you described. Take a careful look at the diagram
    in the following link below. You'll notice that some of the spacers look identical when they
    actually are not.

    http://www.campagnolo.com/pdf/196-Pignoni%2010Speed.pdf

    Kenny Lee
     
  3. peterwright

    peterwright New Member

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    Thanks Kenny

    Will have a good look tonight.
     
  4. Rick Onanian

    Rick Onanian Guest

    On Wed, 18 Feb 2004 06:04:17 GMT, peterwright
    <[email protected]> wrote:
    >engages all cogs correctly. When in the 21 however the chain jumps and skips constantly when under
    >load (both big and small ring). It does not seem to jump cogs but just loses grip and regains it
    >(at least that is what it feels like)

    Sounds like a worn chain or a worn cog. Maybe both, and when you re-assembled you put the 21 on
    backwards, and it's wear no longer matches the chain's wear.
    --
    Rick Onanian
     
  5. Ronald

    Ronald Guest

    > and when you re-assembled you put the 21 on backwards

    I don't think this is possible with the 9/10 speed spline pattern.

    "Rick Onanian" <[email protected]> wrote in message
    news:p[email protected]...
    > On Wed, 18 Feb 2004 06:04:17 GMT, peterwright <[email protected]> wrote:
    > >engages all cogs correctly. When in the 21 however the chain jumps and skips constantly when
    > >under load (both big and small ring). It does not seem to jump cogs but just loses grip and
    > >regains it (at least that is what it feels like)
    >
    > Sounds like a worn chain or a worn cog. Maybe both, and when you re-assembled you put the 21 on
    > backwards, and it's wear no longer matches the chain's wear.
    > --
    > Rick Onanian
     
  6. Peter Wright wrote:

    >>engages all cogs correctly. When in the 21 however the chain jumps and skips constantly when under
    >>load (both big and small ring). It does not seem to jump cogs but just loses grip and regains it
    >>(at least that is what it feels like)
    >
    A well-meaning poster wrote:
    >
    > Sounds like a worn chain or a worn cog. Maybe both, and when you re-assembled you put the 21 on
    > backwards, and it's wear no longer matches the chain's wear.

    Nope, can't be that. You can't put the sprockets on backward on any modern hub (you could on the
    older Shimano Uniglide Freehubs though.)

    Problems related to chain/sprocket wear generally manifest themselves first in the smaller
    sprockets.

    I would have sent this as a private off-list reply if the well-meaning poster had provided a valid
    email address.

    I'm not really sure what is causing Peter's problem, but I suspect what Shimano calls the "b
    tension" adjustment.

    See: http://sheldonbrown.com/derailer-adjustment

    Sheldon "Doesn't Have _All_ The Answers" Brown Evanston, Illinois +-----------------------------------------------------
    +
    | Life is the art of drawing sufficient conclusions | from insufficient premises. --Samuel Butler |
    +-----------------------------------------------------+ Harris Cyclery, West Newton, Massachusetts
    Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
    http://captainbike.com http://sheldonbrown.com
     
  7. peterwright

    peterwright New Member

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    When I now look at the spacingbetween the two fixed parts (25,23 & 21,19) there appears to be a slightly smaller gap then between all other cogs. Dont see how this could be done though as spacers dont look wrong ??
     
  8. peterwright wrote:

    > When I now look at the spacingbetween the two fixed parts (25,23 & 21,19) there appears to be a
    > slightly smaller gap then between all other cogs. Dont see how this could be done though as
    > spacers dont look wrong ??

    Bingo! If the spacing is different there, that's your problem. You're missing some sort of
    spacer. I had the idea that the 21 was the largest sprocket on your cassette, which made it
    inexplicable to me.

    The spacing between each sprocket and the next should be exactly the same. If your 21 is too close
    to your 23, the chain will rub on the side of the 23 and won't engage the 21 smoothly.

    Sheldon "Equal Spacing" Brown Evanston, Illinois +------------------------------------------+
    | So we'll go no more a roving |
    | So late into the night, |
    | Though the heart be still as loving, |
    | And the moon be still as bright. |
    | |
    | For the sword outwears its sheath, |
    | And the soul wears out the breast, |
    | And the heart must pause to breathe, |
    | And Love itself have rest. |
    | |
    | Though the night was made for loving, | And the day returns too soon, | Yet we'll go no more a
    | roving | By the light of the moon. | --Lord Byron |
    +------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone 617-244-
    9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
    http://captainbike.com http://sheldonbrown.com
     
  9. peterwright

    peterwright New Member

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    Do you know if there is a clear picture anywhere of how the different spacers fit on to the cassette - the Campy instructions do not appear clear to me.

    Thanks

    Peter
     
  10. Peter-<< When I now look at the spacingbetween the two fixed parts (25,23 & 21,19) there appears to
    be a slightly smaller gap then between all other cogs. Dont see how this could be done though as
    spacers dont look wrong ?? >><BR><BR>

    Biggest cogs on first, then the thinner of the two 'stepped' spacers, then the next section, then
    the thicker of the two stepped spacers, then the rest of the cogs and spacer.

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

    peterwright New Member

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    I have one larger spacer which is not circular then one that is a ridged circular spacer then three identical non ridged circular spacers.

    At the moment the non circular is between the 25/23 and the 21/19 cogsets and then the ridged circular is between the 21/19 and the 17/16 and then the other three circular non ridged.

    Appears ok to the eye but need to check it on the bike

    Does this make sense as it does not seem to tie with your description of the spacers ...
     
  12. peterwright

    peterwright New Member

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    Ok so now I have tried the cassette again on the bike and it appears that the problem has shifted somewhat. The 19 sprocket (attached to 21) has a jump in it. When I backpedal and look closely I can see the chain moving laterally slightly as it engages the teeth and it is this that is making it jump slightly and make the noise. Any thoughts ??? (I think that the spacers are now correct)

    Thanks

    Peter
     
  13. Carl Fogel

    Carl Fogel Guest

    peterwright <[email protected]> wrote in message news:<[email protected]>...
    > Sheldon Brown wrote:
    > > peterwright wrote:
    > > > When I now look at the spacingbetween the two fixed parts (25,23 & 21,19) there appears to
    > > > be a slightly smaller gap then between all other cogs. Dont see how this could be done
    > > > though as spacers dont look wrong ??
    > > Bingo! If the spacing is different there, that's your problem. You're missing some sort
    > > of spacer. I had the idea that the 21 was the largest sprocket on your cassette, which
    > > made it inexplicable to me. The spacing between each sprocket and the next should be
    > > exactly the same. If your 21 is too close to your 23, the chain will rub on the side of
    > > the 23 and won't engage the 21 smoothly. Sheldon "Equal Spacing" Brown Evanston, Illinois
    > > +------------------------------------------ +
    > > | So we'll go no more a roving |
    > > | So late into the night, |
    > > | Though the heart be still as loving, |
    > > | And the moon be still as bright. |
    > > | |
    > > | For the sword outwears its sheath, |
    > > | And the soul wears out the breast, |
    > > | And the heart must pause to breathe, |
    > > | And Love itself have rest. |
    > > | |
    > > | Though the night was made for loving, | And the day returns too soon,
    > > | | Yet we'll go no more a roving | By the light of the moon. | --Lord
    > > | Byron |
    > > +------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
    > > 617-244- 9772 FAX 617-244-1041 http://harriscyclery.com/http://harriscyclery.com Hard-to-find
    > > parts shipped Worldwide http://captainbike.com/http://captainbike.com[/url]
    > > http://sheldonbrown.com/"]http://sheldonbrown.com
    >
    >
    >
    > Do you know if there is a clear picture anywhere of how the different spacers fit on to the
    > cassette - the Campy instructions do not appear clear to me.
    >
    > Thanks
    >
    > Peter
    >

    Dear Peter,

    Campagnolo dealers may have the kind of manuals that you want. (You know, the useful kind that
    address the obvious questions.)

    Search this page for "exploded" and you'll find some examples of such manuals with lavish praise and
    suspiciously low prices:

    http://www.branfordbike.com/campy/campy.html

    Elsewhere, similar pleas have provoked the usual advice to take pictures with the wonderful new
    inexpensive cameras as you disassemble intricate parts. Some day, I'll buy a camera and try this
    sensible approach.

    Carl Fogel
     
  14. Kenny Lee

    Kenny Lee Guest

    peterwright wrote:

    >
    > Ok so now I have tried the cassette again on the bike and it appears that the problem has shifted
    > somewhat. The 19 sprocket (attached to 21) has a jump in it. When I backpedal and look closely I
    > can see the chain moving laterally slightly as it engages the teeth and it is this that is making
    > it jump slightly and make the noise. Any thoughts ??? (I think that the spacers are now correct)
    >
    > Thanks
    >
    > Peter

    Peter,

    The spacers with the ridges are different widths. They almost look identical. If you get them mixed
    up and in the wrong position then you will have shifting problems. Maybe you should take the bike in
    to an LBS that has experience working with Campy equipment.

    Kenny Lee
     
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