Derailer not working

[Ajax Bay]

I can move derailleur manually and when I let go chain goes directly to the smaller cog.

So what's the problem? Let the cage go. Pull the cable tight, leading it beside the thread of the clamp bolt (which may have a groove on it to show where the cable should go), and clamp. Then operate the shift lever with a steady push: the derailleur arm should move down and a little left, and the cage should move right. Some tweaking will no doubt be required - it nearly always is.

 

[Ming the Merciless]

Thanks for coming back, yes I can move derailleur manually and when I let go chain goes directly to the smaller cog. I will take a couple of photos this PM and forward them to you.

Plus presumably if you pull the cable by hand where it runs down the down tube, you can get the derailleur to move out to the big ring? If that is true it’s pointing to it not being right inside the shifter .

 

[Wolfbaine]

OK I am waiting for my wife to get back to put the bike on a stand, can't do it myself due to disability. In the meantime, I have cut the cable and put farrel on the end. The cable and the barrel adjuster are tight. I can feel cable moving slightly when I pull levers but not enough to move FD. If still not working, I intend to slacken off the barrel adjuster and pull cable tight again. If this fails I'll put up some pictures

 

[Wolfbaine]

Hi guys thanks again for all the helpful advice. Thought I was almost there, got the height and alignment right, then couldn't figure out why the L adjuster would't move cage. When packing away found the chain was not on the large cog on the cassette. Lol, need to d o some more indexing tomorrow

 

[Darius_Jedburgh]

I'm not sure that the position of the chain on the cassette is causing your problems.

 

[Mike_P]

Double check the cables route, I was having all sorts of issues until I flipped the bike upside down and realised the cable had threaded it's way through the moving mechanism so jamming it, from the side / above it had looked okay.

 

[iluvmybike]

Also do check that the shifter is full down in lowest position - some have a trim on them and need anotehr tap to go right down to lowest setting - then pull cable tight & do up pinch bolt. Then use the adjuster to fine tune

 

[Mr Celine]

Its the front no matter how tight I pull the cable the pull arm wont stay above small cog

With the cable slack (or with no cable at all) the derailleur cage should be above the small chainring.

If you mean you're pulling the cable tight before doing up the clamp then it could be you're pulling the cable too hard.

 

[Mike_P]

I'm having similar problems - it started on Monday with the triple front derailleur turning during a ride. I sort of straightened it and since then have been trying to get it to work properly. At best it will only move to the middle chainwheel and at worse I cannot get it off the smallest chainwheel. With the cable slack the derailleur is well inset of the small chainring so has something seriously gone wrong with it?

 

[Mike_P]

Discovered a plastic part that sits on top of the derailleur had started to split so it's presently hopefully being glued back together.

 

[Ajax Bay]

If it matters you won't be able to glue it back successfully (too much stress), and if it doesn't matter, it won't make a difference.

With the cable slack the derailleur is well inset of the small chainring so [I have done] something seriously gone wrong

FTFY
Ensure that, by adjusting the band-on clamp on the seat tube, the cage is parallel with the chainrings and when pushed across over the largest ring, is 2-3mm clear of the teeth (if you can't push the cage far enough across, loosen the H (upper limit) screw (doubt this will be needed).
Ensure the LH shifter is clicked to the lowest point (no tension), with the chain on small/smallest, adjust the lower limit screw till the cage inner plate is 1mm inboard of the chain. Is the cable slack? Tighten it and reclamp. Bit more fiddling and you should be there, and can get more village names. 'Zeal Monarchorum' was one I had to go over a 100km for.

 

[Mike_P]

If it matters you won't be able to glue it back successfully (too much stress), and if it doesn't matter, it won't make a difference.

All I can think of is that by breaking it had managed to increase its depth, the broken part getting underneath the rest, as the low limit screw was having little effect and the screws pass through it.

 

[Ajax Bay]

I know the bit you mean. The limit screws thread into metal: the plastic bit (with two 'holes' in) is there to line the screws up and avoid misalignment.

 

[Mike_P]

Got the plastic bit back together at the second attempt using Araldite that time. Annoyingly it's only a two quid part but seems pretty scarce other than via an Amazon seller from abroad with £20 postage Still however cannot get the shifter to change to the third setting unless I loosen the tension of the cable so much that the actual mech does not move to the middle chainring when the shifter is on the second setting. I can pull the cable to get the chain onto the largest chainring when it is changing with the shifter between the other two. Here's a couple of photos of the mech which seems lined up okay to me; chain is on the smallest freewheel cog and the high limit screw is well undone.

 

[Mike_P]

And another