Stuck on big ring

[ellis]

I have a Spesh Allez with sora gears, the chain is currently stuck on the big ring at the front it wont shift down to the small ring...

Cleaned it this morning and noticed the wire that runs from the shifter to the front derailler is very loose when i try to shift down to the small cog, should it be so loose (see pic)

Is there any easy way to fix this problem anything to do with the tension of the wire?

 

[HLaB]

I'm no expert but I believe If the problem was other way round (ie stuck in the small ring) the lack of wire tension might be a problem as you generally on road bikes pull the wire tighter to shift the derailleur out to the large ring. My guess something is stuck in the limit screw mechanism/ the front derailleur needs re lubing or the low limit screw needs adjusted.

 

[ellis]

rite cheers ill have a look tomorrow morning ill try the low limit screw..

 

[jimboalee]

The mech is stuck.

Common problem if the mech pivots haven't been weatherproofed.

You will have to grab the mech and give it some elbow grease until it moves freely.

Take the bike to a filling station and blow any crud out of the pivots with the air hose while moving it with the changer, NOT your hand. 85 psi air can get through the skin.

Then give it a spray of something that lubes, but dries non sticky.
I use Mr Sheen wax polish.

Don't go fiddling with the limit screws, because they were set up by the LBS and will be in the correct position. They very, very, very rarely move.

 

[ellis]

Ahh o.k sounds like a plan ill check that then see what can be done. Thanks

 

[andrew_s]

It could also be the cable getting stuck where it passes under the bottom bracket - eg cable guides packed full of mud.

 

[Big John]

I reckon Jimbo is right - it sounds like it's stuck. If the cable is slack then by default the front mech should move inwards towards the frame. The fact that it hasn't and has left you in the big ring suggests it's stuck. Lots of cleaning, lots of lube and a touch of elbow grease should free it up. When it's working properly again give it the once over every week. Prevention is better than cure, eh?

 

[RedBike]

GT85

 

[gbb]

The mech is stuck.

Common problem if the mech pivots haven't been weatherproofed.

You will have to grab the mech and give it some elbow grease until it moves freely.

Take the bike to a filling station and blow any crud out of the pivots with the air hose while moving it with the changer, NOT your hand. 85 psi air can get through the skin.

Then give it a spray of something that lubes, but dries non sticky.
I use Mr Sheen wax polish.

Don't go fiddling with the limit screws, because they were set up by the LBS and will be in the correct position. They very, very, very rarely move.

Jimbos almost certainly right..i had this every winter on my Sora front mech. Its salt and corrosion getting into the pivot. Your cables probably loose because the deraieur hasnt shifted down. When you free the mech, the cable shoud come right.
Despair not, its a quick fix.
On the rear of my 8 speed front mech is a largish dome headed, allen key type bolt (looking from the rear wheel). This is the point where the mech pivots. Undo it sightly...(dont undo it altogether) and spray in some GT85, WD40 or ight lubricant and grab the mech and manipulate it some. Once its free, tighten the dome headed bolt.
Done.

 

[ellis]

Superb guys. Got it sorted thanks for the advice did what jimboa and gbb said was just stiff came loose once i undid that allen bolt. Fantastic cheers.

Must remeber to clean my bike properly from now on....

 

[gbb]

Superb guys. Got it sorted thanks for the advice did what jimboa and gbb said was just stiff came loose once i undid that allen bolt. Fantastic cheers.

Must remeber to clean my bike properly from now on....

If only it were that easy . I clean mine regularly at work, spray the mechs with WD40 amost every time i clean it (to drive out any water etc)...it still happens.
I never got as far as undoing the pivot altogether and applying some grease or similar...something a bit more long term.

 

[swee'pea99]

It could also be the cable getting stuck where it passes under the bottom bracket - eg cable guides packed full of mud.

This one got me once. It's the first thing I check now. Shift any crap with an old toothbrush, then a little bit of 3-in-1 and all's well...

 

[jimboalee]

While you are all checking your front mechs, have a try of the cable tension adjuster on the rear mech.

This is THE screw that seizes up.

 

[palinurus]

Just had exactly the same problem with my Sora front mech. For several weeks i've been "double de-clutching" to get it back into the small ring (lever forward, unclip foot, whack meck inwards with foot, clip back in, trim back upwards with lever- i've got pretty good at it too).

Finally got around to cleaning it up, lubed it, worked it about a bit, but it was still not moving freely enough. Had a go at the domed nuts, one loosened nice, the other was a bit tight- gave it some stick and it rounded off. Bollocks.

Finally stuck it in a beaker of propanol and left it in the ultrasonic bath at work. Working again now.

And thanks for that tip, I'll check my rear mech too.