noise after chain change

[Pierre Feller]

Hi,
No noise before the chain change and now a rhythmical metallic noise
only running under pressure (up a hill) and on the middle front blade
(3 x 9 Campagnola Veloce/Daytona)and on the 4 largest cogs.
The new Campagnola C9-chain runs and shifts smoothly - I checked out
each link - on the work-support. The cassette is new, the 3
front-blades have about 7'000 km. This is my second chain change. What
could it be ?
Thanks for your advice, Pierre

[Sorni]

"David Kunz" > wrote in message
link.net...
> Pierre Feller wrote:
>
> > Hi,
> > No noise before the chain change and now a rhythmical metallic noise
> > only running under pressure (up a hill) and on the middle front blade
> > (3 x 9 Campagnola Veloce/Daytona)and on the 4 largest cogs.
> > The new Campagnola C9-chain runs and shifts smoothly - I checked out
> > each link - on the work-support. The cassette is new, the 3
> > front-blades have about 7'000 km. This is my second chain change. What
> > could it be ?
> > Thanks for your advice, Pierre
>
> Gear wear. The spacing is no longer one inch for 2 teeth, but your new
> chain is. They may look fine, but they're worn a little further apart.
> If the noise isn't bad, I'd just let the chain wear into the gears --
> as long as it doesn't skip under load.

Except he said the cassette is new, too. I'm guessing the new chain has a
rivet sticking out a hair (hence, "rhythmical" noise).

Bill "check where chain was broken first" S.

[Sorni]

"Sorni" > wrote in message
.. .
> "David Kunz" > wrote in message
> link.net...
> > Pierre Feller wrote:
> >
> > > Hi,
> > > No noise before the chain change and now a rhythmical metallic noise
> > > only running under pressure (up a hill) and on the middle front blade
> > > (3 x 9 Campagnola Veloce/Daytona)and on the 4 largest cogs.
> > > The new Campagnola C9-chain runs and shifts smoothly - I checked out
> > > each link - on the work-support. The cassette is new, the 3
> > > front-blades have about 7'000 km. This is my second chain change. What
> > > could it be ?
> > > Thanks for your advice, Pierre
> >
> > Gear wear. The spacing is no longer one inch for 2 teeth, but your new
> > chain is. They may look fine, but they're worn a little further apart.
> > If the noise isn't bad, I'd just let the chain wear into the gears --
> > as long as it doesn't skip under load.
>
> Except he said the cassette is new, too. I'm guessing the new chain has a
> rivet sticking out a hair (hence, "rhythmical" noise).
>
> Bill "check where chain was broken first" S.

Just re-read OP. Could be middle chainring wear, I suppose -- but why only
in 4 largest cogs? Sounds like it's related to ANGLE of chain?

Bill "aye, there's the rub, bub" S.

[David Kunz]

Sorni wrote:

> "Sorni" > wrote in message
> .. .
>
>>"David Kunz" > wrote in message
link.net...
>>
>>>Pierre Feller wrote:
>>>
>>>
>>>>Hi,
>>>>No noise before the chain change and now a rhythmical metallic noise
>>>>only running under pressure (up a hill) and on the middle front blade
>>>>(3 x 9 Campagnola Veloce/Daytona)and on the 4 largest cogs.
>>>>The new Campagnola C9-chain runs and shifts smoothly - I checked out
>>>>each link - on the work-support. The cassette is new, the 3
>>>>front-blades have about 7'000 km. This is my second chain change. What
>>>>could it be ?
>>>>Thanks for your advice, Pierre
>>>
>>>Gear wear. The spacing is no longer one inch for 2 teeth, but your new
>>>chain is. They may look fine, but they're worn a little further apart.
>>> If the noise isn't bad, I'd just let the chain wear into the gears --
>>>as long as it doesn't skip under load.
>>
>>Except he said the cassette is new, too. I'm guessing the new chain has a
>>rivet sticking out a hair (hence, "rhythmical" noise).
>>
>>Bill "check where chain was broken first" S.
>
>
> Just re-read OP. Could be middle chainring wear, I suppose -- but why only
> in 4 largest cogs? Sounds like it's related to ANGLE of chain?

This is really the same thing that happened to me -- right down to it
being the largest gears and the middle CR. At the time, I was guessing
that it was because these gears had their sides worn a bit from the
chain angle and from use (I climb a lot of hills). The new chain's
laterally stiffer and highlights this. But, my middle CR had too much
wear to really confirm this by inspection. It went away after a bit (I
don't remember how long it took).

David

[Art Harris]

Pierre Feller wrote:

> No noise before the chain change and now a rhythmical metallic noise
> only running under pressure (up a hill) and on the middle front blade
> (3 x 9 Campagnola Veloce/Daytona)and on the 4 largest cogs.

Is the "rhythmical metallic noise" once per pedal revolution? If so,
it's not the fault of the chain. Check to see if the chain is rubbing
the front derailleur when pedaling hard (possibly due to frame flex).
Try trimming the front der.

Art Harris

[Pierre Feller]

David I think you are right: it is the front middle CR I use the most,
but I always kept it clean and lubrated, so for me it is a great
question: why already wear out ? Ok my weight isn't the slightest: 85
kg...
Pierre

[David Kunz]

Pierre Feller wrote:
> David I think you are right: it is the front middle CR I use the most,
> but I always kept it clean and lubrated, so for me it is a great
> question: why already wear out ? Ok my weight isn't the slightest: 85
> kg...
> Pierre

It's usually one of 3 things: lube, cleaning, or waiting too long to
replace the chain.

You feel that you keep your chain clean and well lubbed (been there,
been disapointed :)). Do you make sure to clean your cassette and
chainrings when you clean the chain? Does your cleaning method get in
between the link plates where crud will wear the sides of the gears?
Next time you think that you're chain's still clean, feel the sides of
the CR teeth and see if there's grit on them. This will wear the sides
and cause the problem that you're having.

You might consider changing to a different lube. I switched from a wet
lube to finish line teflon and my chain and gear life almost doubled.
I'd expect similar results from other semi-dry lubes (they go on thin to
penetrate and set-up into a viscous thick film in 1-2 hours). Also,
always wipe off any extra lube. If you can get to it with a rag, it's
not in the right place to reduce friction :) -- all it'll do is collect
dust and dirt that'll turn into grinding paste.

It could also be that you lube it when there's grit on it, but it may
look fairly clean. This will carry the grit into the chain where it can
do the most damage.

Lastly, if you wait too long to replace the chain, it'll have damaged
the cogs so that the new chain does not fit them right -- the teeth
spacing has worn to match the old chain and they're now too far apart.
The symptom here is usually skipping under power, not noise. But, the
recommended chain replacement time is when 6 full links (2 chain pieces)
measures 6-1/16 to 6-1/8 inch. A new chain'll be 6". Some people
rotate between 3 chains so that they don't have to worry about this
(what I've started doing). All of the chains will wear about the same
and the gears and cogs will match them. When you do finally replace
them, you just replace the whole driveline :) (well, maybe considering
how often I use the big CR, I might get away with leaving it).

David