Campy9 drivetrain clatter

Gene Tolli said:

Hi All,

I'm finishing up a new bike build, and my C9 drivetrain is
making a ruckus. Specifically: Chorus Mk2 12x23 cassette,
SRAM 9s chain, Chorus9 metal shifters.

The noise is cassette based, and only occurs when
*up*shifting to the 15, 14, 13 and (less so) to the 12. I
can quiet the clatter by gently pulling the shift lever,
so it appears the rear der slightly overshifts to the
right. There is no noise at all downshifting, and no noise
upshifting from the 23 to the 16 (all of which correspond
to riveted cogs).

I've replaced the chain and tried a different cassette;
neither helped. Dropouts are aligned. Shift housings have
been cut flush, opened with a scratch awl and filed flat,
and there are no wacky bends in the routing.

I believe the Chorus levers have about 6-7000 miles on
them, and have never been damaged.

My thinking:

1) Time for an Ergo rebuild. Seems unlikely.
2) Double check the hanger alignment. I've checked it and
it seems fine.
3) I have crossed the shift cables under the downtube for
smoother routing. Again, seems unlikely.

Any help appreciated. Thanks in advance.

Regards, Gene Tolli

Sounds like you don't have enough tension when reattaching
the cable to the RD. The cable should be pulled tight and
then bolted down.

Kenny Lee

geetee-<< The noise is cassette based, and only occurs when
*up*shifting to the 15, 14, 13 and (less so) to the 12. I
can quiet the clatter by gently pulling the shift lever, so
it appears the rear der slightly overshifts to the right.

Quoted message said:

Quoted message said:

<BR><BR>

Either the inner wire is not moving back and forth smoothly
insiode the housing or you may have a broken EC-RE-111,
spring carrier with a post, that breaks. You describe a
broken post on the EC-RE-111..Easy to fix, not expensive.
You can check it by removeing the lever from the hbar,
taking the little cover off the back and you will see the
opst end, at the 1 oclock of the shift guts. If it is loose
like a loose tooth, it is broken.

If nobody locally 'qui si parla Campagnolo', send it to me
for a 1 day turnaround.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St.
Boulder, CO, 80302
(303)440-3535 vecchios.comvecchios.comOpen ↗ "Ruote convenzionali
costruite eccezionalmente bene"

Gene Tolli said:

The noise is cassette based, and only occurs when
*up*shifting to the 15, 14, 13 and (less so) to the 12. I
can quiet the clatter by gently pulling the shift lever,
so it appears the rear der slightly overshifts to the
right. There is no noise at all downshifting, and no noise
upshifting from the 23 to the 16 (all of which correspond
to riveted cogs).

All Ergos, including brand new ones*, have some play which
means slightly too much cable is released when the thumb
button is pressed. This is taken up next time the downshift
lever is used.

To avoid this, users either increase cable tension or live
with it (and some have never noticed the flaw or deny it's
a problem).

* I've noticed this with three new pairs: One Chorus and
two Mirages.

~PB

Quoted message said:

Gene Tolli said:

The noise is cassette based, and only occurs when
*up*shifting to the 15, 14, 13 and (less so) to the 12. I
can quiet the clatter by gently pulling the shift lever,
so it appears the rear der slightly overshifts to the
right. There is no noise at all downshifting, and no
noise upshifting from the 23 to the 16 (all of which
correspond to riveted cogs).

I think the chain is noisier in the smaller sprockets
because adjacent sprocket is only on tooth different - it's
higher up - top of teeth are nearer chain, to rub against.

~PB

Quoted message said:

Gene Tolli said:

The noise is cassette based, and only occurs when
*up*shifting to the 15, 14, 13 and (less so) to the 12. I
can quiet the clatter by gently pulling the shift lever,
so it appears the rear der slightly overshifts to the
right. There is no noise at all downshifting, and no
noise upshifting from the 23 to the 16 (all of which
correspond to riveted cogs).

ps. riveted cogs are not relevant because I get the same
problem with Veloce 9-speed cassettes which have no
riveted cogs.

~PB