Front derailleur spring problem
#1
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Front derailleur spring problem
First time poster here. I noticed recently I was unable to shift my front gears and quickly discovered there is nothing keeping the derailleur in desired position. I'm assuming there is a problem with the spring but have never had any experience in this either. Can you tell from the two photos below if the problem is the spring? In the second photo, on my index finger is one of the spring ends. But as you can see...it doesn't really make contact (stop) with anything to engage the spring. This was another family members bike that was passed down to me for commuting. Unfortunately, the previous owner is in another town and can not really help me out with what I'm experiencing.


Am I looking at new front derailleur in my immediate future? Any help would be greatly appreciated.
Sincerely,
B.

Am I looking at new front derailleur in my immediate future? Any help would be greatly appreciated.
Sincerely,
B.
#2
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From: Fife Scotland
Bikes: Airnimal Chameleon; Ellis Briggs; Moulton TSR27 Moulton Esprit
Difficult to tell from the photos but if you undo the cable the FD should spring back to the smallest ring position (nearest the frame) and have considerable tension. If it does not, then lubricate and clean the FD but if this doesn't work then a new one seems in order.
#3
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From: Near St. Louis, Missouri
Bikes: Giant Defy Advanced, Breezer Doppler Team, Schwinn Twinn Tandem, Windsor Tourist, 1954 JC Higgens
I'm thinking that it might be the shifter that's the problem. Like Onbike suggested, undo the pinch bolt that holds the cable and see if the FR moves freely then.
#4
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Let me see if I can better explain it. If I loosen the cable (or change to the smaller two gears,) the FD just freely pivots back and forth (in and out) without any tension. I will try to take a video and upload it when I get home tonight. In the meantime, I found another photo of the backside of the derailleur. In the photo below, on the left side of the black spring, it appears that the extended portion of the spring makes contact with a pivoting arm (?) which allows the spring to create tension. However, in the photos of my initial post, you can see there is nothing there for it to contact. I'm wondering if that extended portion on that side of the spring has broken off, making it too short to reach the contact point it needs to create the required tension.

Again, I'll take a video tonight. Thanks for the replies.

Again, I'll take a video tonight. Thanks for the replies.
#5
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Worse case scenario, I have to purchase a new front derailleur. I've been searching for a replacement and am having troubles finding many options for a triple 8-speed. Would I be able to go with a triple 9-speed or triple 10-speed? I ask about those because there seems to be more options. I apologize for these basic questions. If this were a car, I'd be more fluent in solving my problem. But with this bike (any bike,) I have no experience.
#6
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Joined: Apr 2007
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From: Syracuse, NY
Bikes: 2008 Novara Randonee - love it. Previous bikes:Motobecane Mirage, 1972 Moto Grand Jubilee (my fave), Jackson Rake 16, 1983 C'dale ST500.
You are correct that the spring end has broken, pretty clear that it can provide no tension if not anchored and the fact the derailleur freely moves back and forth confirms the problem. You will indeed need to replace the derailleur. A triple 9 speed should not be a problem, and even a 10 will not offer a lot of problems.
Last edited by cny-bikeman; 07-09-13 at 02:06 PM.
#7
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From: Boulder County, CO
Bikes: '80 Masi Gran Criterium, '12 Trek Madone, early '60s Frejus track
You are correct that the spring end has broken, pretty clear that it can provide no tension if not anchored and the fact the derailleur freely moves back and forth confirms the problem. You will indeed need to replace the derailleur. A triple 9 speed should not be a problem, and even a 10 will not offer a lot of problems.
That spring anchoring nubbin breaking off is my number one cause of Shimano road front derailleur failure. It's more robust on the 10-speed units.
#8
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Thanks for the replies. I figure there is no need to take a video and upload it. I'm almost certain it's toast. I'll purchase a new one. I found what appears to be the same derailleur on ebay... better safe than sorry.
#9
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From: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
This derailleur isn't quite toast yet. But the decision whether to save it rests on the availability of a suitable replacement. If there is one, just buy it.
However, if there's nothing decently comparable, drill out the head on the rivet on the lower arm (the one with the spring). Push out the pin, and slide the spring off. Scavenge the junk derailleur bin, for one with the same spring (Shimano probably uses the same spring on a number of FDs). Rebuild FD with new (used) spring, using a screw and nut in lieu of the riveted lower pivot pin. Either use Loctite or distort the threads so nut doesn't work loose.
However, if there's nothing decently comparable, drill out the head on the rivet on the lower arm (the one with the spring). Push out the pin, and slide the spring off. Scavenge the junk derailleur bin, for one with the same spring (Shimano probably uses the same spring on a number of FDs). Rebuild FD with new (used) spring, using a screw and nut in lieu of the riveted lower pivot pin. Either use Loctite or distort the threads so nut doesn't work loose.
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#10
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Well, I was able to take a closer look at the derailleur, this time with more appropriate lighting. If you look at the last photo above, there is a bit of metal from the pivot arm that extends at the bottom and covers the lower left corner of the spring (according to the photo.) It is what the spring contacts to create the tension. Unfortunately, that little extension has busted off mine rendering my derailleur currently useless. I'm sure I could take the approach of trying to scavenge a replacement pivot arm but I don't have a junk derailleur bin, just a couple of tubes with holes. $25/shipped for the same replacement derailleur. I'll keep in mind the way to "fix" it for next time, thank you FBinNY.
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