Stuck in the big ring...

[Andy in Germany]

Having managed to change my cassette and chain without breaking any more tools, I've hit a new problem. My front mech won't move the chain from the big ring to the middle ring. Changing the tension in the cable got it working, but then it rattled when I was using the middle ring and went to the smallest gear on the cassette.

What is especially annoying is that it worked fine yesterday morning on the way to work, but on the way back it just rattled when I tried to change down.

The mech hasn't been moved and worked fine before. I adjusted the limiter screw as it was throwing the chain when I changed to the big ring, but the only real difference -apart from a new chain- was from a 7 to 8 speed cassette, but I can't see how that makes a difference as there was a spacer on the 7 speed so the small gear would be in roughly the same place relative to the big ring.

I may as well blame the weather as it was cool on the way in and hot on the way back...

 

[Racing roadkill]

The mechs rarely go back to the exact same positions, after you change up or down, unless your running very high end components, and even then, they still tend to ‘wander’ a bit, that’s why we have trim adjusters on the cables.

 

[T4tomo]

The mechs rarely go back to the exact same positions, after you change up or down, unless your running very high end components, and even then, they still tend to ‘wander’ a bit, that’s why we have trim adjusters on the cables.

that's my nomination for least helpful post if the day sorted

OP, hard to say. One thought is did you tweak the right limiter screw if it now isn't dropping to small ring?

maybe worth slacking cable right off and re setting it up following a Park Tool video on You Tube.

also is the cable a bit sticky - may be worth replacing if it is, that may be stopping the FD returning to its resting position

 

[raleighnut]

It feels left out.

Seriously though it's a cable tension issue, the middle ring indexing is controlled by cable tension only but like already posted a sticky cable will interfere with this.

 

[Racing roadkill]

that's my nomination for least helpful post if the day sorted

OP, hard to say. One thought is did you tweak the right limiter screw if it now isn't dropping to small ring?

maybe worth slacking cable right off and re setting it up following a Park Tool video on You Tube.

also is the cable a bit sticky - may be worth replacing if it is, that may be stopping the FD returning to its resting position

 

[Globalti]

If you haven't changed the cable outers in more than a couple of years, changing them will make a huge difference.

 

[Ajax Bay]

The mech hasn't been moved and worked fine before.

The mechs rarely go back to the exact same positions, after you change up or down, unless your running very high end components, and even then, they still tend to ‘wander’ a bit, that’s why we have trim adjusters on the cables.

I occasionally have difficulty telling whether Rr is joking / taking the p*ss. In this case: no difficulty whatsoever. I wonder how many hundred times my front and rear 'mechs' have gone back to "the same place" just in the 1000k and 600k rides completed in the last 20 days. Of course Rr may wish to elaborate what is meant by "exact same".
Edited to add: Since no answer (or reference) to this I will guess Rr has me on 'ignore'.
Advice to OP: do what @Globalti and @T4tomo have suggested above.

 

[Rooster1]

Being stuck in a big ring is not pleasant at all.

 

[Milkfloat]

Being stuck in a big ring is not pleasant at all.

Surely better than being stuck in a small ring

 

[TheDoctor]

The mechs rarely go back to the exact same positions, after you change up or down, unless your running very high end components, and even then, they still tend to ‘wander’ a bit, that’s why we have trim adjusters on the cables.

Sorry, but that's absolute nonsense. I don't touch my trip adjusters from one year to the next.

 

[User6179]

What is the new chain width?, I have bought 8 speed chains in the past which turned out to be narrower 9 speed chains, only found out when I went to fit 8 speed quick link and it was loose.

A narrower chain means the mech has to travel further to move the chain.

 

[Racing roadkill]

Sorry, but that's absolute nonsense. I don't touch my trip adjusters from one year to the next.

It isn’t “nonsense” try riding more. My triples are a nightmare for having slightly ‘wandery’ front mechs. It rarely means they won’t shift all the way around the rings, but nearly always means there’s a trim adjustment required, after a couple of hundred kilometres, to keep them from rubbing the front mech, especially if there’s been a change of components ( anything from cables, to rings or chains ). I’ve never known it to be any different, and I know I do lots more riding than you ever have.

 

[Racing roadkill]

Being stuck in a big ring is not pleasant at all.

Try lube.

 

[Tim Hall]

It isn’t “nonsense” try riding more. My triples are a nightmare for having slightly ‘wandery’ front mechs. It rarely means they won’t shift all the way around the rings, but nearly always means there’s a trim adjustment required, after a couple of hundred kilometres, to keep them from rubbing the front mech, especially if there’s been a change of components ( anything from cables, to rings or chains ). I’ve never known it to be any different, and I know I do lots more riding than you ever have.

I'd suggest you use a different mechanic.

 

[TheDoctor]

It isn’t “nonsense” try riding more. My triples are a nightmare for having slightly ‘wandery’ front mechs. It rarely means they won’t shift all the way around the rings, but nearly always means there’s a trim adjustment required, after a couple of hundred kilometres, to keep them from rubbing the front mech, especially if there’s been a change of components ( anything from cables, to rings or chains ). I’ve never known it to be any different, and I know I do lots more riding than you ever have.

Bully for you.
Perhaps learn how to set up your gears? Although we've wandered OT here.