Bicycle Mechanics - Can't shift to Big Chainring

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View Full Version : Can't shift to Big Chainring


dhale50
03-11-08, 08:12 AM
Couldn't find anything in search function. Ok it seems that all the rear cogs are shifting fine. When I start to shift the front chainring from small to large, the shifter wont engage (I don't hear that last "click" from my shift lever).

When I shift, the chain will engage the large chainring (still no "click" and at this point I have not released the lever I am just pushing it in). But as soon as I release the lever it falls back down to the small ring.

Is there an FD barrel adjuster I have to use? If so, where is it? If it makes any difference this is Campy Centaur 10 speed. I don't know if this is a shifter problem or FD issue. Thanks


cyccommute
03-11-08, 08:57 AM
Couldn't find anything in search function. Ok it seems that all the rear cogs are shifting fine. When I start to shift the front chainring from small to large, the shifter wont engage (I don't hear that last "click" from my shift lever).

When I shift, the chain will engage the large chainring (still no "click" and at this point I have not released the lever I am just pushing it in). But as soon as I release the lever it falls back down to the small ring.

Is there an FD barrel adjuster I have to use? If so, where is it? If it makes any difference this is Campy Centaur 10 speed. I don't know if this is a shifter problem or FD issue. Thanks

Probably cable stretch. There should be an adjuster on the downtube near the headset or there should be an in-line adjuster.

Downtube adjuster

http://i144.photobucket.com/albums/r181/cyccommute/Las-Cruces-top-tube.jpg

In-line (this one is on a brake cable)

http://i144.photobucket.com/albums/r181/cyccommute/IMG_0332.jpg

dhale50
03-11-08, 09:11 AM
Thank you.


Retro Grouch
03-11-08, 09:16 AM
Was it ever right?

If it used to work and now it doesn't I'd agree with the "cable stretch" theory.

If it never worked right I suspect you need to loosen your high gear limit screw about 1/4 turn.

dhale50
03-11-08, 09:57 AM
Was it ever right?

If it used to work and now it doesn't I'd agree with the "cable stretch" theory.

If it never worked right I suspect you need to loosen your high gear limit screw about 1/4 turn.

Yes it was right. Then I started trying to adjust the FD because I shifted while pedaling (big to small) and the chain dropped. Now I can't get the thing to shift back into the big.

Also, I can't find a downtube or inline adjuster on these Campy cables. Is this Campy specific?

Retro Grouch
03-11-08, 10:09 AM
Yes it was right. Then I started trying to adjust the FD because I shifted while pedaling (big to small) and the chain dropped. Now I can't get the thing to shift back into the big.

Also, I can't find a downtube or inline adjuster on these Campy cables. Is this Campy specific?

Some bikes don't have a front derailleur barrel adjuster.

The first thing I would do would be to try the 1/4 turn on the high limit screw. Believe it or not, sometimes if that screw is too tight it can make your chain overshift your small chainring, so it might solve both problems.

If that doesn't do it, put the chain on your small ring, disconnect your shift cable and shift into your lowest front shifter position. Pull the cable just taut with a needle nose pliers and reattach it.

cyccommute
03-11-08, 11:48 AM
Some bikes don't have a front derailleur barrel adjuster.

The first thing I would do would be to try the 1/4 turn on the high limit screw. Believe it or not, sometimes if that screw is too tight it can make your chain overshift your small chainring, so it might solve both problems.

If that doesn't do it, put the chain on your small ring, disconnect your shift cable and shift into your lowest front shifter position. Pull the cable just taut with a needle nose pliers and reattach it.


And install an in-line adjuster at some point. It's pretty easy.

dhale50
03-11-08, 11:52 AM
cool! thanks guys

rickowensis
03-11-08, 11:47 PM
Couldn't find anything in search function. Ok it seems that all the rear cogs are shifting fine. When I start to shift the front chainring from small to large, the shifter wont engage (I don't hear that last "click" from my shift lever).

When I shift, the chain will engage the large chainring (still no "click" and at this point I have not released the lever I am just pushing it in). But as soon as I release the lever it falls back down to the small ring.

Is there an FD barrel adjuster I have to use? If so, where is it? If it makes any difference this is Campy Centaur 10 speed. I don't know if this is a shifter problem or FD issue. Thanks

Probably cable stretch which can be adjusted by turning front shifter in-line adjuster counterclockwise approx. 1 turn to increase cable tension. You'll have to experiment a little to get it right. Meanwhile, here's a good source of info: http://parktool.com/repair/readhowto.asp?id=75

Barabaika
03-12-08, 01:30 AM
Don't you have instructions with pictures for your front derailleur?
You can download them here: http://www.campagnolo.com/repository/documenti/en/7225360_Front_derailleur_0407.pdf

Quote:
If the chain does not climb on the large chainring:

* the cable is too loose: loosen the adjusting screw (C - Fig. 11) on the casing fastening block.
* the end-of-stroke adjustment is incorrect: loosen screw (B- Fig. 11) (1/4 of a turn at a time).