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-   -   Please help ASAP, front derailleur locked up (https://www.bikeforums.net/showthread.php?t=1186213)

Liquidspacehead 10-21-19 11:13 AM

Please help ASAP, front derailleur locked up
 
https://cimg9.ibsrv.net/gimg/bikefor...ad4916620e.jpg
https://cimg2.ibsrv.net/gimg/bikefor...d55b24a345.jpg
My front derailleur has stopped moving all together. The shifter also doesn't seem to be reading the gear correctly I will be attaching pictures. Any help is appreciated

pdlamb 10-21-19 11:30 AM

Top picture looks like there's some rust on the derailer. Take a finger or two and pull the front derailer cable outwards from the downtube. If the derailer moves, the problem's in the shifter or cable housing. If it doesn't, prepare the penetrating oil "bath"!

Liquidspacehead 10-21-19 11:35 AM

Nothing moved. What now? I have a video as well but it wont let me post it... anyway what could the problem be? Something seems locked. The shifting doesn't seem to anything at all to the derailleur

*Scuba 10-21-19 11:41 AM

Have you tried the following? When the front mech does not shift properly, I work down the list to see what is the cause.

1) Push on the front derailleur itself, the easiest point is the pivot arm where the cable is pinched. Can the derailleur move back and forth.
- If the derailleur cannot move, something is seized or broken
- If the derailleur moves, but does not snap back into the lowest gear default setting, spring might be gummed up

2) Try pulling on any exposed front shift cable, can you get the front derailleur to move back and forth and change gear whilst you rotate the pedal?
- If you can get the front mech to move and shift gears, problem is not the derailleur or cable/housing but the shifter itself
- If the front mech cannot move, even when you pull very hard on exposed shift cable, the cable itself is most likely seized within the housing due to corrosion

3) Push and click through your shifter, is the tactile feeling positive? I only do this step after I have gone through step one and two.
- If the pawls are not catching properly, shifter might be gummed up and need a solvent flush and relubricate
- If you feel the pawls catching and releasing normally, most likely a cable/housing issue. For example a worn cable and housing or cable tension is too low.

jimc101 10-21-19 12:34 PM

Not seeing any significant rust on the FD, and Shimano FD's are pretty rust-resistant.

What happens when you undo the cable? the FD should return to the lowest position, and you should be able to manipulate it with your hands at this point.

When the cable is undone, you can also see if there is any resistance/lack of movement if you use the shifters.

One other thing, it looks like you spend a lot of time in the middle ring, sort of hard to tell from the angle of the photo, but the chainring looks a little pointy and you may want to consider replacing it (the middle ring) at some point.

JohnDThompson 10-21-19 01:16 PM

Disconnect the cable from the derailleur and operate the shifter. Does the cable move smoothly and easily when disconnected? If not, you may need to lubricate the shifter, replace the cable and/or housing. While the cable is still disconnected, use your hand to move the derailleur cage in and out. Does it move easily (taking spring tension into account) and smoothly? If not, the derailleur needs lubrication. Lubricate freely until the unit moves easily and smoothly. Reconnect the cable, check adjustment, and it should be ok.

freeranger 10-21-19 03:02 PM

A long shot, but it happened to me once--have you checked to see if a small stone might have gotten thrown into the der. and is stopping it from moving? Also--looks like both high and low limiting screws are turned in the same amount--hardly ever see that-might be ok on yours, but looks odd to me.

HillRider 10-21-19 07:53 PM

Are you turning the crank while trying to move the derailleur by hand? Unless the chain and crank are moving the derailleur can't shift it and will appear "locked up". Incidentally, your pictures tell me next to nothing by themselves.

Andrew R Stewart 10-21-19 09:31 PM

One thing I see in the photos is a well worn middle ring. The tooth profile at about 11:00 is getting pretty scallaped/sharp tipped.

As some have mentioned it's easy to separate each component of the system and test each. Andy

Slightspeed 10-21-19 10:27 PM

I had a broken Tiagra FD, and it turned out to be the black, coiled tension spring that snaps the derailleur cage back and forth. The fix was to upgrade to an Ultegra FD. I don't have the pieces any more, or I would post a picture.

Heres an article I found regarding a broken spring on Tiagra:

https://www.******.com/r/bikewrench/comments/5tok4o/fix_broken_spring_front_derailleur/

trailangel 10-22-19 09:06 AM

Cable not routed correctly. Read the instructions.

Wilfred Laurier 10-22-19 10:04 AM

I suspect that the cable is incorrectly routed, as @trailangel said. This will make the derailleur movement very stiff at the shift lever, but not necessarily lock it. Many front derailleurs have a washer with a tab under the cable pinch bolt, and the cable is supposed to go over the tab, which may be non-intuitive when you are setting it up.

To the OP: did you do any work on the bike before it stopped working? Like adjustments to the derailleur? It is a possibility that the two limit screws are turned in too far. Their job is to stop the derailleur from moving past the inner and outer chainrings, and if they are turned in to far they can stop the derailleur moving almost completely.

Liquidspacehead 10-22-19 10:21 AM

I recently changed the gear cable and I dont believe I shifted the shifter correctly before reinstalling the cable. I am leaving town for a festival but for now I took my derailleur off and removed the cable to essentially run a ghetto 1x to get me to and from work just for the last day I am in town. And then I will keep you guys posted on the end result. Also a small piece of metal fell out of my shifter once i removed the cable (that was REALLY in there idk why my cable was so jammed) but now it seems to shift flawlessly. So we will see when I return! Thank you all

trailangel 10-22-19 05:08 PM


Originally Posted by Liquidspacehead (Post 21174869)
I recently changed the gear cable and I dont believe I shifted the shifter correctly before reinstalling the cable. I am leaving town for a festival but for now I took my derailleur off and removed the cable to essentially run a ghetto 1x to get me to and from work just for the last day I am in town. And then I will keep you guys posted on the end result. Also a small piece of metal fell out of my shifter once i removed the cable (that was REALLY in there idk why my cable was so jammed) but now it seems to shift flawlessly. So we will see when I return! Thank you all

ASAP help response was given... you need to cancel any plans going forward and fix this ASAP to satisfy the forum.


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