Shifting problem (record 10)

peterwright said:

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.

campagnolo.com196 Pignoni%2010Speed.pdfOpen ↗

Kenny Lee

Quoted post said:

Originally posted by Kenny Lee

Bpeterwright said:

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.

campagnolo.com196 Pignoni%2010Speed.pdfOpen ↗

Kenny Lee [/B]

Thanks Kenny

Will have a good look tonight.

peterwright said:

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

Quoted message said:

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

Quoted message said:

peterwright said:

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

Peter Wright said:

Quoted message said:

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 said:

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: sheldonbrown.comderailer adjustmentOpen ↗

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 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

Quoted post said:

Originally posted by Sheldon Brown

BPeter Wright said:

Quoted message said:

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 said:

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: sheldonbrown.comderailer adjustmentOpen ↗

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 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗ [/B]

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 ??

peterwright said:

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 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

Quoted post said:

Originally posted by Sheldon Brown

Bpeterwright said:

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 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗ [/B]

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

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 vecchios.comvecchios.comOpen ↗ "Ruote convenzionali costruite eccezionalmente bene"

Quoted post said:

Originally posted by Qui Si Parla Ca
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 vecchios.comvecchios.comOpen ↗ "Ruote convenzionali costruite eccezionalmente bene"

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 ...

Quoted post said:

Originally posted by peterwright
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 ...

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

peterwright <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Sheldon Brown said:

peterwright said:

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" rel="ugc nofollow noopener">harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find
parts shipped Worldwide "]http://captainbike.com/http://captainbike.com[/url]
sheldonbrown.comsheldonbrown.comOpen ↗"]sheldonbrown.comsheldonbrown.comOpen ↗

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:

branfordbike.comcampy.htmlOpen ↗

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

peterwright said:

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