Indexing problem on Campag 2009 rear derailleur

GeorgeShaw

I'm having problems adjusting the indexing on my new bike. It's all Campag 2009, mainly Centaur Carbon, with a 13-29 cassette, but with a medium cage Chorus rear derailleur.

The end stops are OK, but when adjusting the cable tension I'm finding that, while the middle of the cassette changes OK, the change is reluctant when changing from larger to smaller cogs on the largest gears, but in the second smallest gear the drive is noisy as the derailleur is between the second and first cog. i.e. the indexing distance doesn't seem to be the same as the cog spacing.

Any ideas why this should be and what I can do to correct it?

Monty Dog

Firstly, have you checked that you have the cassette spacers in the right order - look at the gaps on the cassette - are they all consistent? Also, Campagnolo recommend you set up indexing from the middle of the cassette i.e. sprockets 5/6 rather than the smallest sprocket - like Shimano. It shouldn't make a difference, but worth a try. Also check things like chain length and cable routing.

on-yer-bike

GeorgeShaw wrote:

I'm having problems adjusting the indexing on my new bike. It's all Campag 2009, mainly Centaur Carbon, with a 13-29 cassette, but with a medium cage Chorus rear derailleur.

The end stops are OK, but when adjusting the cable tension I'm finding that, while the middle of the cassette changes OK, the change is reluctant when changing from larger to smaller cogs on the largest gears, but in the second smallest gear the drive is noisy as the derailleur is between the second and first cog. i.e. the indexing distance doesn't seem to be the same as the cog spacing.

Any ideas why this should be and what I can do to correct it?

Try turning the cable tension screw on the derailleur clockwise a quarter turn at a time.

GeorgeShaw

The tension screw is what I've been playing with. Adding an extra quarter turn just makes it noisier in the second smallest gear - you can see visually that the derailleur is sitting between the first and second gear and the cable is slack in the smallest gear as it's now up against the end stop. Yet there is still reluctance to change to a smaller gear when on the larger ones - say a 3 or 4 second time lag sometimes a lot longer.

So my inclination was to turn anti-clockwise to take out the slack and align the derailleur with the small gears properly, but then there is even more reluctance to change on the large gears.

I've checked the channels under the bottom bracket and they look clear. The cables are nearly new and the routing looks OK, unless there's a problem under the tape or hoods.

It's a bit odd, because I've ridden my now number 2 bike for 3 years on 9-speed Xenon/Mirage mix with only a half-turn adjustment. Solid as a rock.

I'm presuming that this couldn't be anything do with the Chorus mech (the indexing being set by the ergos not the mech) and/or the dinner-plate cassette ...

Monty Dog

Just checking that it's not a Chorus 11 rear mech? The fact that it is sluggish on the downshift suggest that you have cable drag - the spring tension in the rear mech parallelogram 'pulls' the cable back through.

GeorgeShaw

It will be Chorus 11 - as it's also 2009 - but that shouldn't make a difference, should it?

I just checked the alignment, and in fact on the big gears the derailleur is still to the left (looking from the rear) - as it is for the small gears. So I think you're right, there must be some drag on the cable that's causing the reluctant changes. All I'm doing by putting slack into the cable is using the spring tension to overcome the drag and force the change, reducing the reluctance. But that's just leading to other problems (the noise) in the small gears.

Better to have the mech correctly set up and find out why the cable's dragging.