Front derailleur won't move chain to small chainring

[Maz]

Hello

Spesh Allez Elite...

Just recently, the front derailleur is not moving the chain from the big to the small chainring.

Even when the chain is on the big chainring, the derailleur "cage" thing is starting to rub occasionally against the chain.

Do I need to adjust either of the 2 screws in the picture?

I thought I'd better ask, because I would probably choose the wrong screw and then also turn it in the wrong direction and make things worse and then I'd regret touching it in the first place. Many Thanks.

 

[Gerry Attrick]

Unless you have bent the mech, and assuming it was working ok a bit back, then I would first clean and lubricate all the pivots and cable. Check the cable isn't frayed. You can clean everything with GT85, but dry it off thouroughly and re lube with a wet chain lube.

 

[Maz]

Unless you have bent the mech, and assuming it was working ok a bit back, then I would first clean and lubricate all the pivots and cable. Check the cable isn't frayed. You can clean everything with GT85, but dry it off thouroughly and re lube with a wet chain lube.

Thanks. Will do. I've got some GT85 and chain lube.

Noticed it today after a very wet ride home the night before. Plenty of muck on the road that night. Maybe a good clean and lube is all that's needed.

A good clean/lube was also what was needed when I had sticky rear brake blocks recently.

 

[swee'pea99]

Beaten to the mark. Lube everything that could be sticking - cables and all pivot points. Then if that doesn't work, think again.

 

[Maz]

Thank you, sir.

 

[PatrickPending]

for future reference

http://bicycletutor.com/adjust-front-derailer/


previous replies have nailed the issue I'd guess - I used to find sora mechs would start sticking all the time (no problem with the limiting screws) and needed a good clean/lube however ultegra i've yet to have one stick and I've done a fair few miles in all weathers - better design I guess

 

[gbb]

for future reference

http://bicycletutor....front-derailer/


previous replies have nailed the issue I'd guess - I used to find sora mechs would start sticking all the time (no problem with the limiting screws) and needed a good clean/lube however ultegra i've yet to have one stick and I've done a fair few miles in all weathers - better design I guess

My Sora mech siezes every winter, without fail.
To nail it down even further, the offending bit is the large dome headed screw at the pivot. Look at it from the back wheel. Undo it slightly, lube then re-tighten. Works every time.

 

[Maz]

Hm, I cleaned and lubed what i could without undoing or adjusting any bits n bobs.
Derailler still won't pull the chain over to the small chainring.
According to the bike's spec the derailler is
Front Derailleur: Shimano Tiagra bottom pull with a 31.8mm clamp.
What could I try next to solve this problem?
This bike is my daily commuter, so the problem is starting to niggle me on the uphills.

 

[Graham1]

I had a similar problem a couple of weeks ago turned out the cable guide under bottom bracket was bunged up with mud.

 

[Maz]

Can anyone help me with this one, please?
Further suggestions?

Hm, I cleaned and lubed what i could without undoing or adjusting any bits n bobs.
Derailler still won't pull the chain over to the small chainring.
According to the bike's spec the derailler is
Front Derailleur: Shimano Tiagra bottom pull with a 31.8mm clamp.
What could I try next to solve this problem?
This bike is my daily commuter, so the problem is starting to niggle me on the uphills.

 

[Gerry Attrick]

Maz, you could do more harm than good by adjusting stops and cables willy nilly. Have several good perusals of this and this and then try adjusting if you feel competant. The thing is, derailleurs do not generally just go out of adjustment.

If necessary, take the bike to a good lbs. If I lived nearer Leicester, I would happily sort it for you.

 

[Fattman]

This applied in my case to the rear derailleur - but hear me out! - I had trouble shifting from big to small on the rear and it turned out that the cable had frayed in the brake/gear lever itself. This meant that the spring was unable to pull the cable cleanly, so it would be really naughty about moving properly.

Now, this was the rear cable, which generally gets worked a lot more, but it's happened twice (same Tiagra shifter both times, once with Tiagra mech, the other Ultegra). I guess it could potentially have happened on the front too but I have changed all the cables and it may simply not have gotten to that point.

Not saying it's your problem, but worth a quick squizz if and when, as previous poster said, you're comfortable with twiddling with cables, undoing screws etc. and if other stuff doesn't solve it.

Matt

 

[gwhite]

I'm aware that you have tried to lube the FD but do try this before adjusting anything as the FD does not go out of adjustment by itself.
Change to the inner chainring and then grip the gear cable where it runs down the frame. Rotate the pedals by hand and while doing this pull down the cable so that the FD tries to move over the full range of its arc. Lube and do this again as it can be very sticky. If this does not work then the cable should be disconnected from the FD and the FD tested by moving it by hand over its full arc. If it can do this then the problem is usually in the cable but in most cases the problem is a sticky FD.

 

[Maz]

Thanks for the help thus far...I need to spend more time investigating this [difficult getting the time, work, kids, family life, shopping, etc!].

I had a closer look at the Front derailleur and noticed that there was a protective plastic cover on a very tightly-wound spring...so when I was lubing the FD the other day, I was putting lube on the plastic cover by mistake (see poor quality picture)

I've now applied lube to the spring and...(wait for it...)...I still can't get the FD to move the chain to the small chainring. I can't even push the FD by hand to move it on to the small chainring.

I'll have to try some of the suggestions above and see if that fixes the problem.
Will let you know how I get on! Thanks.

 

[HLaB]

Before you start fiddling with the limit screws (if it was ok before it still be ok, limit wise) check like other have said the cables are they running freely and/or check the mech and make sure no grime or anything is upsetting it, remember to lube other bits like the pivot point.