rear deraillieur not working?

Question

my rear deraillieur stopped working today, although not completely. It shifts to the larger rear sprockets but it will no longer shift back to the smaller sprockets. The cable slackens and tightens so the shifter is fine, but the deraillieur will not shift the chain. It looks OK, but perhaps the spring has broken inside it?

Answer 1

Either:
Gear cable and outer want replacing (cheap)
Gears want indexing (free if you know how to do it otherwise pay for labour)
Rear derailleur siezed (can be fixed cheaply)
rear derailleur wants replacing (still not ever so expensive)

Answer 2

It's possible that your cable has stretched too much and there is not enough tightness in the cable to pull the derailer far enough.
If thats not the case, look at the derailer from the rear, put the gear into it's highest setting and see if the jockey wheels of the derailer line up with the highest (Smallest) gear of the casette, If not then it's either a cable problem or the derailer range is being hampered by the screw settings. Take it to the shop and get it fixed initially, but if you want to do it yourself, the Haynes Bike maintenance book is a great technical guide and has good diagrams and photos to help you sort out most problems you will encouter with your bike.

Answer 3

You haven't mentioned how old it is or how much of a beating it's taken, but if it won't shift down then there's a chance that it's damaged.
Are you sure the cable slackens all the way off?

Basically if you don't know what your doing take it to a bike shop and have them fix it.

There's an article here that explains how derailers work better than I ever could.


Hope this helps!

-=D=-

Answer 4

Braided steel cables can stretch a little during constant use, and in most cases, there are a couple of little screws at the derailer that help control the "play" of motion that it has. It may simply be that either the derailer is out of adjustment, or in a worse case scenario, the cable itself is fraying inside its protective sleeve, and thus not moving like it should.
Good luck.

Answer 5

It is difficult to say. Is your deraillieur old, rusty, beat up, etc? If the cable is moving with the shifter, maybe the cable is loose and isn't tightened to the deraillieur. Can you move the deraillieur by hand?

Your best bet is to take it to a bike shop and have them look at it.

Answer 6

I would say its probably the last bit of cable where it goes back into the inner that is rusted up, This time of year cables suffer a bit, its not a big job and not expensive, you might even be able to get away with just an outer.

Answer 7

Maybe the spring in the deraileur is loose, and doesn't have the strenght to return the shifter up.

Go to a bike shop, they'll know how to fix it, or if not, it's time for an upgrade ;)

Answer 8

you have got two scews the upper and the downer try undoing both of them if that dose not work try spraying the derailleur and the cables with a lube.you might need a new cable,cost about £2.99 and is quite easy to fit...

Answer 9

try unscrewing the "H" screw on the derailleur to allow it to shift higher. look from behind to see if the hanger is bent. if the derailleur does not hang straight down, they you have a problem with the hanger. most can be replaced with $15-20.

Answer 10

it depends - if it's an expensive derailuer take it to the shop

but if not (or have some knowlage on this) look for the screws on the unit, and check there allignment before you play

tutorials may help