Problem with Campagnolo Veloce Ergo Chain Jumping Off Large Chainring .

[Illaveago]

My brother is having a problem changing up onto the large chainring . At first it was okay but has now been jumping off . I spent a couple of hours with him the other day trying to set it up .
We turned the front mech stops in out shake it all about. Removed the front mech to make the mounting more round by filing some high spots so it fitted the seat tube better .
We got it to change successfully but has now slipped again so that it jumps off and ends up on the crank .
It changes down fine .
Whilst watching him change whilst on a stand the chain will go beyond the chainring at the front before returning to its correct position. If we adjust the stop inwards it will not engage the chainring .
He seems to think that the cable is slipping in the front brake / gear lever ?
Does anyone know what might be happening ?
I just tried my old Campag down tube shifters on my old Viking and it goes straight onto the large chainring .

 

[Ajax Bay]

My first check would be to make sure that there was no more than 1mm clearance between the FD cage and the top of the large chainring teeth. Next I would ensure the FD cage plate is accurately parallel to the chainring. If no joy I would angle the FD cage in very slightly (tail closer to frame).

 

[Paulus]

Has he recently cleaned the chain?
I had a similar problem after a through clean. I measured the chain and it was worn well over the limits that a chain should be replaced.

 

[Illaveago]

The bike is new to him . It has been well looked after.
The mech was working fine on his first test ride but has since been playing up .
I was wondering if the chain might be worn .
The front brake lever changers are strange to me . I prefer chatter chatter silent manual down tube gear levers .
I have been doing some reading and chatting with my brother . It seems as though they operate on a ratchet system . 2 clicks of the lever should be enough to change up to the top ring . The push button seems to release the ratchet to drop back to the lower ring .
He has now got back to me saying that it will not change up to the larger chainring ! To me it sounds as though the cable is too tight and not allowing the ratchet to engage fully .
Do you ever feel like clipping people ?
I have read a bit about the cable being too tight can cause this problem.
I think he should try a new chain and start off at the beginning again with everything slackened off .

 

[Cycleops]

If you think you've done all you can on the derailleur maybe change the cable inner and outer and give the brifter a good spray with WD40 or similar.
A new chain might be an idea anyway.

 

[Illaveago]

Latest news seems to be that there is excess slack in the cable . He is going to pull back the hood to see if the other cable is shedding the outer sheath and pulling through.

 

[Smokin Joe]

I was wondering if the chain might be worn .


I think he should try a new chain and start off at the beginning again with everything slackened off .

A worn chain won't effect shifting.

 

[Ajax Bay]

This is not the chain.
And not being able to get onto the large ring is not too much tension, it's too little (or the H limit screw is screwed in too much (assurance from the OP exists on this)).
Check the nipple in the Ergo is seated properly. Check the outer cable is seated properly both ends. Check under the BB shell that it's running smoothly.
Your brother needs to get this 'Mummy Bear': not so far that the chain falls off outwards and enough tension in that final click to push the chain far enough to lift onto the ring.

 

[Illaveago]

My brother has peeled back the hood and found that the cable hasn't been returning to its stop so that when things were adjusted there was still slack in the system . He is going to investigate it further tomorrow .

 

[Cycleops]

They can get gummed up, hence my post. I recently brought a misbehaving brifter back to life with a good flushing of WD40.