Campagnolo shifting issue

rowlers

Gears shift flawlessly up and down, apart from the 3 largest sprockets. It will NOT drop from the 27 with 1 click, I've to click 2 down and shift 1 back up to keep it sweet, same for next 2. After that they are sweet as a nut.
This is 2010 10sp Centaur

I'm guessing cables (but I really CBA changing cables at present - its internal cabling!), so any other tips?

mattbell

I've had similar issues with my bikes. There are various things which may help"

Clean your groupset.
Check your train for stretch / wear.
Check your derailleur hanger isn't bent
Consider replacing cables, is there any friction / or bent outer cable housing? I found by making the rear cable which bends into the RD about 2cm longer made a massive difference.
Make sure all your cable end caps are the campag metal ones not the plastic shimano ones.

rowlers

mattbell wrote:

I've had similar issues with my bikes. There are various things which may help"

Clean your groupset.
Check your train for stretch / wear.
Check your derailleur hanger isn't bent
Consider replacing cables, is there any friction / or bent outer cable housing? I found by making the rear cable which bends into the RD about 2cm longer made a massive difference.
Make sure all your cable end caps are the campag metal ones not the plastic shimano ones.

Cheers I intend to give the bike a good going over ASAP as I've got a big 2 day ride coming. So will certainly look into those too.

drlodge

Here's an easier check...the body tension screw aka "B screw" on the rear dearailleur. With the chain on the 27T sprocket, how much of a gap is there between the upper jockey wheel and the sprocket? There should not be alot. Too much of a gap will affect shifting in the way you describe

Refer to this guide http://www.parktool.com/blog/repair-hel ... derailleur



The campag screw works the opposite way round to Shimano, so to bring the upper jockey wheel closer you need to turn the tension sdrew clockwise I think.

"In this system, the upper spring is fixed. Increasing cage tension (turning screw clockwise) will bring the upper pulley closer to the cog. Decreasing cage tension (turning screw counter-clockwise) will increase the distane between upper pulley and cog."

rowlers

drlodge wrote:

Here's an easier check...the body tension screw aka "B screw" on the rear dearailleur. With the chain on the 27T sprocket, how much of a gap is there between the upper jockey wheel and the sprocket? There should not be alot. Too much of a gap will affect shifting in the way you describe

Refer to this guide http://www.parktool.com/blog/repair-hel ... derailleur



The campag screw works the opposite way round to Shimano, so to bring the upper jockey wheel closer you need to turn the tension sdrew clockwise I think.

"In this system, the upper spring is fixed. Increasing cage tension (turning screw clockwise) will bring the upper pulley closer to the cog. Decreasing cage tension (turning screw counter-clockwise) will increase the distane between upper pulley and cog."

Excellent, that is something to try. Does the chain need to be on or during adjustment? Have have fiddled with the B screw, but it doesn't appear to do alot! :oops:

drlodge

If you take the chain off, you will get a better feel for what that screw is doing. The acid test is with the chain on though, if you have a workstand then try changing the gears while turning the cranks and see if it improves.

A trick I use with the chain off, is to eye ball the upper jockey wheel to see if its exactly inline with the sprockets as you index the rear shifter. It might be that your rear derailleur is a smidge out of alignment, requiring a little shortening using the barrel adjuster (as cables tend to stretch).

rowlers

cool, i'll try with chain off, then check again with chain on.
I bet this is the issue!

rowlers

Update, you were bang on with the b screw. adjusted and now we have flawless shifts all through the cassette.
Happy!

marathon50

Having the same problem with Campagnolo Chorus 11speed
rear deraliieur. When using the last 3 low gears
jockey wheels catching the block and the chain is slack. New chain, block and jockey wheels fitted chain correct length and jockey wheels upper and lower correct position.
Was working perfect before replacing just seems to be no tension in the rear derailleur to stop chain from bouncing and hitting the block when in those last 3. I have tried adjusting the b screw but makes no difference.Is there anywhere that has instructions or shows you how to service and put extra tension on the derailleur. I think if I can get a extra bit of tension it will solve my problem.
Thanks