Rear derailleur issue.

[zyjk]

Hi,

During the winter, I'd been riding in deep mud and wet conditions and found eventually that the rear derailleur would not work properly, hard to change from high to low and the return from low to high would not work.

I took the derailleur off and cleaned it with petrol and oiled it and replaced, there was still a difficulty so today I checked the cable and found the cable movement was restricted through the housing due to rust and mud. I have now changed the cable but, still have the issue where i can change from high to low gear but the derailleur will not return from low to high (the movement actioned by the spring action of the derailleur). But if I apply harder tension to the cable the selector will click back as if changing from low to high.

Difficult to describe, but maybe this will be familiar to someone who may be able to advise what should be done.

I am assuming the possibility that that the derailleur spring is worn out and I need to replace the derailleur. Might I be correct?

 

[qwiksilver]

probably best to replace if you have exausted all other options but maybe its not the spring it could be the pivot points seized or the gear selector itself

 

[zyjk]

thanks, gear selector seems fine as it works when i put tension on the cable, by hand, this was my assumption, but I posted in here because i had read elsewhere that derailleurs are supposed to last for ages??!?! this is the second year of owning the bike, derailleur is the sram x4

 

[qwiksilver]

i personally would work the deraleur by hand moving it in and out with some wd40 but not wd40 lol the stuff that removes rust wd10????? something like that give it a good spray on all pivot points and then move it by hand to loosen any build up of rust or oxidisation and see if that helps b4 i would replace it

 

[the_mikey]

Does the derailleur return to it's resting position without the cable attached, does it spring back with some force?

 

[compo]

With the cable disconnected can you manually move the mech through it's range of movement, and does it move smoothly. This will tell you if the mech is partially seized. If it doesn't there's your problem. if it does then you have troubles with your cables or shifters. Once sorted, when you ride through mud and water then you need to clean and lubricate the mech regularly to avoid problems.

 

[zyjk]

thanks, I just tried moving the derailleur in towards the wheel and leave it go to spring back and it does move very freely, this is really odd as the derailleur moves freely, the gear selector does work, but requires more force than what the derailleur gives to move from low to high gear.

I have renewed the cables and they are nicely oiled and also move nice and freely !!! grrr

 

[qwiksilver]

seems a bit of a conundrum u said it requires alot of force to move from high to low which sounds like the cables but then say it wont go back from low to high which sounds like the mech i know you have renewed the cables i assume both inner and outer and they move freely you said as does the mech so only thing left is the gear selector , try disconecting the selector and changing the gears by hand from that side of the system

 

[qwiksilver]

hmmm another thought just crossed my mind check where the cables enter the cable stops and make sure there are no snags

 

[rusty bearing]

Quicksilvers point. You say 'I've changed the cables' but have you renewed the outers?

 

[zyjk]

haven't removed the outers so will consider that also, thanks all

 

[gbb]

hmmm another thought just crossed my mind check where the cables enter the cable stops and make sure there are no snags

Make sure the cable is connected correctly at the derailleur, make sure the cable is routed correctly, particually under the BB. Its easy to misroute it while its underneath and out of sight.

Make sure the outers are snugly inserted into the stops on the frame.

Bear in mind you've fitted new inners which means you may well have some fiddling to do anyway to get things adjusted correctly (cable tension wise)

 

[amaferanga]

New cable outers as well as inners should sort it if the mech moves freely by hand when disconnected. If the inners were rusted up then it's always a good idea to change inners and outers. Make sure you tidy the cable ends of the outers when you cut them using a file otherwise you can get friction between the inner and outer and crappy shifting.

 

[subaqua]

New cable outers as well as inners should sort it if the mech moves freely by hand when disconnected. If the inners were rusted up then it's always a good idea to change inners and outers. Make sure you tidy the cable ends of the outers when you cut them using a file otherwise you can get friction between the inner and outer and crappy shifting.

use the old cable inner as a former for when you cut the outer , lovely clean cut as the inner helps the outer not to deform. the new inner will push the waste bit out when threaded

 

[fossyant]

haven't removed the outers so will consider that also, thanks all

Doh.

Change them. Oh and clean the mech and cables more often. My mate fubar'ed his brand new front XT mech in 3-4 months by not cleaning it, or applying a bit of WD40 over the winter. Expensive mistake.