Chain "slap" on Campy CF RD

[Artoi]

Has anyone ever come across this issue of chain slap on the CF arm of
their RD?

I have a Campy Record CT setup with a short arm RD. The whole system
essentially works well, quiet and efficient. But when I am on the 19 or
21 rear cog (12-25 cassette with 50 at the front), I would get this
repetitive tapping sound coming from the rear. The tapping noise
disappears when I move to the 23 or 17 and beyond, where the system runs
silent again. On close examination on a repair stand, I think I've
identified the source of the mystery sound to be contacts b/n the chain
and the CF arm of the RD.

I have tried to fine tune the cable tension/RD alignment without
improvement.

So does anyone have any suggestion as to what the problem could be or
how it might be corrected? I was wondering if the H screw setting has
any relevance in this matter? As a matter of fact, what should be the
criteria for setting the H screw?

Thanks in advance.
--

 

[Chalo]

Artoi wrote:
>
> On close examination on a repair stand, I think I've
> identified the source of the mystery sound to be contacts b/n the chain
> and the CF arm of the RD.

It sounds like you are not using the approved Brev. Camp. carbon fiber
composite chain.

Cafone! Cornuto! Figlio di buona donna!

Chalo

 

[sergio]

On Oct 15, 8:41 am, Chalo <[email protected]> wrote:

> Cafone! Cornuto! Figlio di buona donna!

What would that be in plain English?

Sergio
Pisa

 

[[email protected]]

On Oct 15, 1:12 am, Artoi <[email protected]> wrote:
> Has anyone ever come across this issue of chain slap on the CF arm of
> their RD?
>
> I have a Campy Record CT setup with a short arm RD. The whole system
> essentially works well, quiet and efficient. But when I am on the 19 or
> 21 rear cog (12-25 cassette with 50 at the front), I would get this
> repetitive tapping sound coming from the rear. The tapping noise
> disappears when I move to the 23 or 17 and beyond, where the system runs
> silent again. On close examination on a repair stand, I think I've
> identified the source of the mystery sound to be contacts b/n the chain
> and the CF arm of the RD.
>
> I have tried to fine tune the cable tension/RD alignment without
> improvement.
>
> So does anyone have any suggestion as to what the problem could be or
> how it might be corrected? I was wondering if the H screw setting has
> any relevance in this matter? As a matter of fact, what should be the
> criteria for setting the H screw?
>
> Thanks in advance.
> --

Assuming you have a 10 speed setup, check if you have the spacers in
the correct position. With 10 speed cassettes, at least on the Veloce-
Mirage, there are 3 or 4 different spacers of about three different
widths. On Centaur-Chorus-Record cassettes there are fewer spacers
since some of the cogs are bolted together. But there are still a
couple different widths of spacers. You may have a thinner spaceer
where a thciker one needs to be. That is one nice thing about 9 speed
Campagnolo, all the spacers are identical.

I think on the Campagnolo website you can find PDF tech documents that
show the correct order of spacers.

 

[Chalo]

sergio wrote:
>
> Chalo wrote:
>
> > Cafone! Cornuto! Figlio di buona donna!
>
> What would that be in plain English?

Why, I'm sure you already know that would be as follows:

"Oaf! Cuckold! Son of a good woman!"

The words translate easily into English. The essence of the words,
not so much.

Chalo

 

[A Muzi]

Artoi wrote:
> Has anyone ever come across this issue of chain slap on the CF arm of
> their RD?
>
> I have a Campy Record CT setup with a short arm RD. The whole system
> essentially works well, quiet and efficient. But when I am on the 19 or
> 21 rear cog (12-25 cassette with 50 at the front), I would get this
> repetitive tapping sound coming from the rear. The tapping noise
> disappears when I move to the 23 or 17 and beyond, where the system runs
> silent again. On close examination on a repair stand, I think I've
> identified the source of the mystery sound to be contacts b/n the chain
> and the CF arm of the RD.
>
> I have tried to fine tune the cable tension/RD alignment without
> improvement.
>
> So does anyone have any suggestion as to what the problem could be or
> how it might be corrected? I was wondering if the H screw setting has
> any relevance in this matter? As a matter of fact, what should be the
> criteria for setting the H screw?

Is the cog spacing even? A misplaced spacer perhaps?
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[Artoi]

In article <[email protected]>,
"[email protected]" <[email protected]> wrote:

> On Oct 15, 1:12 am, Artoi <[email protected]> wrote:
> > Has anyone ever come across this issue of chain slap on the CF arm of
> > their RD?
> >
> > I have a Campy Record CT setup with a short arm RD. The whole system
> > essentially works well, quiet and efficient. But when I am on the 19 or
> > 21 rear cog (12-25 cassette with 50 at the front), I would get this
> > repetitive tapping sound coming from the rear. The tapping noise
> > disappears when I move to the 23 or 17 and beyond, where the system runs
> > silent again. On close examination on a repair stand, I think I've
> > identified the source of the mystery sound to be contacts b/n the chain
> > and the CF arm of the RD.
> >
> > I have tried to fine tune the cable tension/RD alignment without
> > improvement.
> >
> > So does anyone have any suggestion as to what the problem could be or
> > how it might be corrected? I was wondering if the H screw setting has
> > any relevance in this matter? As a matter of fact, what should be the
> > criteria for setting the H screw?
> >
> > Thanks in advance.
> > --
>
> Assuming you have a 10 speed setup, check if you have the spacers in
> the correct position. With 10 speed cassettes, at least on the Veloce-
> Mirage, there are 3 or 4 different spacers of about three different
> widths. On Centaur-Chorus-Record cassettes there are fewer spacers
> since some of the cogs are bolted together. But there are still a
> couple different widths of spacers. You may have a thinner spaceer
> where a thciker one needs to be. That is one nice thing about 9 speed
> Campagnolo, all the spacers are identical.

That's a good thought that I should double check. I am 99.99% sure the
various spacers were correctly placed in the cassette. I followed
Campy's PDF document when I cleaned and reinstalled just two weeks ago.
It's been the same situation before and after. Yes, it is a 10 speed
setup.
--

 

[Artoi]

In article <[email protected]>,
Chalo <[email protected]> wrote:

> Artoi wrote:
> >
> > On close examination on a repair stand, I think I've
> > identified the source of the mystery sound to be contacts b/n the chain
> > and the CF arm of the RD.
>
> It sounds like you are not using the approved Brev. Camp. carbon fiber
> composite chain.

The don't exist!
--

 

[Artoi]

In article <[email protected]>,
A Muzi <[email protected]> wrote:

> Artoi wrote:
> > Has anyone ever come across this issue of chain slap on the CF arm of
> > their RD?
> >
> > I have a Campy Record CT setup with a short arm RD. The whole system
> > essentially works well, quiet and efficient. But when I am on the 19 or
> > 21 rear cog (12-25 cassette with 50 at the front), I would get this
> > repetitive tapping sound coming from the rear. The tapping noise
> > disappears when I move to the 23 or 17 and beyond, where the system runs
> > silent again. On close examination on a repair stand, I think I've
> > identified the source of the mystery sound to be contacts b/n the chain
> > and the CF arm of the RD.
> >
> > I have tried to fine tune the cable tension/RD alignment without
> > improvement.
> >
> > So does anyone have any suggestion as to what the problem could be or
> > how it might be corrected? I was wondering if the H screw setting has
> > any relevance in this matter? As a matter of fact, what should be the
> > criteria for setting the H screw?
>
> Is the cog spacing even? A misplaced spacer perhaps?

It is. The spacer possibility was raised and has now been eliminated.
I've double checked and it's not the cause. The contact point appeared
to be at the lower end next to the lower jockey wheel of the RD arm
rather than at the upper end.

Totally baffled.
--