Stuck 105 derailleur

[brokenbus]

My 5700series 105 front derailleur will not change down to the small ring even though it has cable slack. It will change if you push it. It happened a month ago so I lubes all the pivot points with silicon spray and worked it back and forward until it was working again. I haven't ridden the bike since until today and back to the same problem. I have got it going again by lubing and working the mechanism but was wondering is this a common thing and do I need a new derailleur if lubing the pivots is only a temporary measure?
Thanks
Nicko

[OnTrackZeD]

Try degreasing it before you relube it.

[ValleyForge]

I lubes all the pivot points with silicon spray and worked it back and forward until it was working again.

Can I ask why silicone spray?
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[Duck!]

Try degreasing it before you relube it.

That won't do anything. It needs a corrosion-breaker.

[brokenbus]

I lubes all the pivot points with silicon spray and worked it back and forward until it was working again.

Can I ask why silicone spray?
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I have a can of it with a fine nozzle so I can accurately spray it where I want. I works great as a lube on door locks.

[brokenbus]

Try degreasing it before you relube it.

That won't do anything. It needs a corrosion-breaker.

Hi Duck can you be more specific with what a corrosion breaker is?
I put some innox on it last night which is a better form of WD 40.
I also have some liquid lithium grease spray- worth a shot of this.

[ValleyForge]

PTFE perhaps on door locks. Silicone spray for nylon garage door runners.

Once the corrosion is cleaned off per Duck!'s post, some standard gear lube might be in order.

Hope it is easier to take apart than my Campy R/SR FDs. E-washers flicking all over the garage.

[lone rider]

Is the spring broken?

[AndrewCowley]

The FD is the only place I use WD40. I find anything else just doesn't get into where it needs to. I also have a 105 5700 FD and have been told that it getting stuck / gummed up is a known issue. Mine once got so bad that it wouldn't move at all. WD40 fixes it for me. I now apply it regularly.

[Duck!]

Is the spring broken?

Doesn't sound like it. If the spring or its locating tab were broken the derailleur would be able to move very freely, just not able to pull itself to the low gear position. It's stuck, which screams out corroded pivot pins & bushings, or a bent derailleur body.

[Duck!]

Hope it is easier to take apart than my Campy R/SR FDs. E-washers flicking all over the garage.

5600 & later derailleurs are rivetted together, so completely impossible to pull apart. 5500 & older models were bolted, so could easily be dismantled for service, with no e-clips to fly everywhere.

[Duck!]

Try degreasing it before you relube it.

That won't do anything. It needs a corrosion-breaker.

Hi Duck can you be more specific with what a corrosion breaker is?
I put some innox on it last night which is a better form of WD 40.
I also have some liquid lithium grease spray- worth a shot of this.

Corrosion breaker, for want of a better term, is exactly that; a product intended for getting in & freeing corroded parts. WD40 is passable, Inox is better, but there are also other products to do that.

Degreaser is exactly what its name implies, a product for dissolving grease, and that's completely irrelevant to the problem at hand. In fact, many degreasers are quite alkaline, which also makes them rather corrosive, so if anything will make the problem worse.

[brokenbus]

Thanks everyone for the comments. I will keep the lube up to the pivots. I have thought about it and are probably guilty of keeping it too clean and not lubing the pivots at all.