Rear deraileur too close to sprocket...and an apology

[Jim]

First an apology for the wasted bandwidth, in my previous hurry to get my question answered I
blurted out 3 messages with various corrections, this message is corrected.

I have just installed and adjusted: Chorus Med cage rear deraileur. Centaur 13-29 rear (10
spd) cassette

Chorus 53/39 crankset and front deraileur

When in biggest cog /small crank my RD cage/top jockey wheel "bobbles" and makes a racket I presume
its too close to the sprocket.

One shift down and smooth as silk, shift into the big front also smooth (in all gears)

I have adjusted the B adjust screw CCW all the way out to no avail. What should I do?

I am leaning towards the chain being, maybe, one link too long, but I sized it (I think) properly.

thanks

jim

[email protected]

jim

[email protected]

 

[Pete Biggs]

jim wrote:
> I am leaning towards the chain being, maybe, one link too long, but I sized it (I think) properly.

Check it. See: http://www.parktool.com/repair_help/FAQchainlength.shtml

If chain is longer than necessary for the big-big, removing a link will work wonders.

Replacing the b-tension screw for a longer one is another option - although a last-resort-type one.

~PB

 

[Pete Biggs]

Just out of interest, how can a message be made "no longer available on the server". This would be
most useful for some of my blunders!

~PB

 

[Qui Si Parla Ca]

ex-<< When in biggest cog /small crank my RD cage/top jockey wheel "bobbles" and makes a racket I
presume its too close to the sprocket. << I have adjusted the B adjust screw CCW all the way out to
no avail. What should I do?

Take a link outta the chain. With a double and a mid cage rear der, the distance from the cage to
the chain when in small/small is pretty big, like 15-20mm, but you will still have enough chain for
big-big combo-

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Bob Taylor]

Using the B tension screw too much causes shifting performance to degrade.

I don't know about Campy but I found a trick that works very well with Shimano rear derailleurs. The
9 speed ones come with 11 tooth pulleys. If you replace the top one with a 10 tooth one from a
Shimano 8 speed RD the bit of extra clearence will often solve the chattering problem when you're
using the largest rear cog (especially the really large ones like a 34 with a mountain derailleur).
There might be a way to make this trick work with Campy.

Bob Taylor

jim <[email protected]> wrote in message news:<BAD3423A.1AE2%[email protected]>...
> First an apology for the wasted bandwidth, in my previous hurry to get my question answered I
> blurted out 3 messages with various corrections, this message is corrected.
>
>
> I have just installed and adjusted: Chorus Med cage rear deraileur. Centaur 13-29 rear (10 spd)
> cassette
>
> Chorus 53/39 crankset and front deraileur
>
> When in biggest cog /small crank my RD cage/top jockey wheel "bobbles" and makes a racket I
> presume its too close to the sprocket.
>
> One shift down and smooth as silk, shift into the big front also smooth (in all gears)
>
> I have adjusted the B adjust screw CCW all the way out to no avail. What should I do?
>
> I am leaning towards the chain being, maybe, one link too long, but I sized it (I think) properly.
>
> thanks
>
> jim
>
> [email protected]
>
>
>
>
>
> jim
>
> [email protected]