Help with contrary left ergo shifter

[Don777]

The past two rides my left shifter has been acting up. It is a Campy Veloce 2006 model on a triple chainring with only 5900 miles. It shifts perfectly on the stand, but not on the road. The problem - it will shift up to larger rings the way it always has and will even click up one more notch to get it trimmed in the middle or large chainring. But occasionally it will not shift down, it might trim down one notch, but not shift on down to a smaller chainring. I can push on the thumb shifter with all of my might and it will not shift down. I can wiggle the thumb shifter sometimes and it will shift back down.
What do you suggest is the problem and the solution?

 

[John M]

The past two rides my left shifter has been acting up. It is a Campy Veloce 2006 model on a triple chainring with only 5900 miles. It shifts perfectly on the stand, but not on the road. The problem - it will shift up to larger rings the way it always has and will even click up one more notch to get it trimmed in the middle or large chainring. But occasionally it will not shift down, it might trim down one notch, but not shift on down to a smaller chainring. I can push on the thumb shifter with all of my might and it will not shift down. I can wiggle the thumb shifter sometimes and it will shift back down.
What do you suggest is the problem and the solution?

I could be that some dirt is in the ratchet part. Maybe try flushing out with some WD40 and re-lube.

Interesting that it shifts on the stand, but not the road.

 

[alfeng]

What do you suggest is the problem and the solution?

I agree, in part, that "dirt" may be the problem ...

But, I think the problem may be your cable ... pull it out, wipe it off, re-lube it ... OR, if you are a bit on the lazy side, shoot some WD-40 into the housing ...

 

[Eastway82]

I agree, in part, that "dirt" may be the problem ...

But, I think the problem may be your cable ... pull it out, wipe it off, re-lube it ... OR, if you are a bit on the lazy side, shoot some WD-40 into the housing ...

The other possible is the rubber hood is obstructing the mechanism - I've had this happen a few times, always on the left shifter, which has a weaker main spring than the right one so maybe it's just more obvious. There should be a little moulding on the rubber hood on the narrow bit under the main body where it goes between the mechanism and the bar. This should fit in a slot in the main body. But with the bars taped, that slot's usually covered over, so that part of the rubber hood can move around, and gets itself caught in the mechanism, locking it up. Bet that's the problem.

BTW, in my experience if you flush out the mechanism on any ergo with WD40 or similar, it's best to take the hood off first - otherwise the solvents in the WD attack the hood and it'll soon go loose.

 

[Don777]

Thanks to John M, alfeng, & Eastway 82. I shot some WD-40 into the ratchet mechanism, blew it out, made sure the bottom of the rubber hood was in the notch, and got a little WD-40 into the housing. Something or a combination of all of the above worked. No malfunctions on my ride today. BTW, I am typically not lazy, I will pull the cable out and clean the housing and replace the cable but that will be during a day when there will be no possibility of riding.
Again, much thanks to y'all for being so kind. Don

 

[sogood]

These two posts seemed to be linked in nature.

http://www.cycling.net.au/t383820.html

The key is most likely to not touch the shift pedal when hitting the thumb button.

 

[BrianNystrom]

These two posts seemed to be linked in nature.

http://www.cycling.net.au/t383820.html

The key is most likely to not touch the shift pedal when hitting the thumb button.

This is a lesson Campy users have to learn; if you push both the shift paddle and the "mouse ear" at the same time, it will not shift. You'd be surprised how easy it is to do this by mistake.