Non-shifting front derailleur... any help here?

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TwoPlusTen
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Non-shifting front derailleur... any help here?

Postby TwoPlusTen » 18 Mar 2009, 8:53pm

Another question...

The front derailleur on my wife's 2008 Rockhopper is not shifting off the largest chain ring. The cable moves when I try to change down, but nothing happens other than the chain loosening slightly and slipping like you'd hear before it changes.

Any suggestions as to what's causing it?

Answers in idiot-proof English please, I'm very not technical...

Thanks all!!

diapason
Posts: 475
Joined: 6 Jan 2007, 7:13pm
Location: West Somerset, UK

Re: Non-shifting front derailleur... any help here?

Postby diapason » 18 Mar 2009, 9:02pm

Is the cable too slack? Check whether it is actually pulling on the derailleur when you operate the shifter. If it's slack, then the adjustment is obvious: loosen the knut which attaches the cable to thederailleur, pull the cable to take up the slack, and retighten. Or, is the cable jammed or broken? Otherwise, is anything stopping the derailleur moving? maybe a small stone, or perhaps the derailleur itself has become slack and slipped down the downtube to foul the chainring - easy to realign and tighten up.

Good luck,

Nigel
Advena ego sum in Terra

TwoPlusTen
Posts: 531
Joined: 12 Apr 2008, 9:02am
Location: Reading
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Re: Non-shifting front derailleur... any help here?

Postby TwoPlusTen » 18 Mar 2009, 9:14pm

diapason wrote:Is the cable too slack? Check whether it is actually pulling on the derailleur when you operate the shifter. If it's slack, then the adjustment is obvious: loosen the knut which attaches the cable to thederailleur, pull the cable to take up the slack, and retighten. Or, is the cable jammed or broken? Otherwise, is anything stopping the derailleur moving? maybe a small stone, or perhaps the derailleur itself has become slack and slipped down the downtube to foul the chainring - easy to realign and tighten up.

Good luck,

Nigel


Hi Nigel,

Thanks for your suggestions.

To answer your questions:

1) Yes, the cable is pulling on the derailleur. Will try that though.
2) The cable is not jammed or broken that I can see. Also nothing stopping the deraileur moving - that i can see at least...
3) There is good clearance from what I can see. Nothing's obviously moved.

Any more thoughts anyone?

dmiller
Posts: 145
Joined: 11 Sep 2007, 1:38pm
Location: Glasgow, Scotland.

Re: Non-shifting front derailleur... any help here?

Postby dmiller » 18 Mar 2009, 9:41pm

My rockhopper came with the standard deore front derailer and I had a similar issue.

Under the limit screws there is a black tube covering the spring and as its tight to the spring it fills up with crud. I snapped it off (its not a full tube and can be removed and refitted but sounds like its snapping), cleaned the spring with a toothbrush and WD40, covered with grease and re-fitted the plastics.

Works a lot better now. Dunno if this helps, your mileage may vary, do this at your own risk etc.

David.

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cycleruk
Posts: 5477
Joined: 17 Jan 2009, 9:30pm
Location: Lancashire

Re: Non-shifting front derailleur... any help here?

Postby cycleruk » 19 Mar 2009, 4:55pm

Pull on the cable at the derailleur end at the same time operate the changer - see if it moves freely.
Is this a top pull or bottom pull?
If a bottom pull then check where the cable goes under the bottom bracket.
You'll never know if you don't try it.

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rbrian
Posts: 851
Joined: 4 Mar 2009, 7:43pm
Location: Aberdeen

Re: Non-shifting front derailleur... any help here?

Postby rbrian » 19 Mar 2009, 5:11pm

Ask Sheldon.
Cynic? No, an optimist tempered by experience.