Adjusting Front Derailleur

[JMerring]

I have a Campy Chorus front derailleur. Just took my bike in to LBS for a tune-up. Overall, they did a fairly decent job. However, pre-tune up, there was chain rub only when riding in the 53-25. Now, there is a varying amount of chain rub when riding in the two immediately higher sprockets as well.

Question is: how do I adjust the front derailleur? I'd prefer to learn how to do it myself rather than to have to take back to the LBS.

A related question is whether chain rub in the 39-12 is unavoidable, or if this is fixable as well.

(Let's not get into whether there are similar gear ratios when riding in the 39 chainring - there are just times when I like being in the 53-25.)

Thanks in advance for your help!

[rinconryder]

parktool.com has a great website. Go to the repair link. It has pictures and instructions on how to adjust most things. If not that, check out a Zinn bicycle repair book - also a good resource in my opinion. Hope those help.

[chrisroph]

First, there is never a reason to ride in a 53xlargest rear cog or 39xsmallest rear cog except if you are having mechanical difficulties of some sort--like you are in a race going up a fast hill and you can't shift out of the 53, or you have snapped a cable. Re f drlr adjustment, there are several different schools but what I find works best on my c 10 rigs is to align the outer cage with the large chainring and mount the drlr so that it just clears the big chainring teeth. you will need to run the drlr through its range of motion and rotate the ring. Then, it is a question of adjusting the stop screws so that the chain just clears the inside of the drlr cage in 39xlargest rear cog, and so that it just clears the outside of the drlr cage in the 53xsmallest cog. Make sure the cable runs free and has no slack and you should achieve max performance with minimal chance of dropping the chain and minimal rub. You will get some rub in the extreme cross over gears if you choose to run them. However, doing so will cause excess friction, wear and noise but it may garner you some extra room in the group. However, the people giving you extra room are likely the people you should be riding near.

[R2D2]

Campagnolo site has detailed and precise instructions for all their gear.