DaveLeeNC

I have a 2014 Chorus groupset on my older Bianchi. I went out for a ride today and suddenly the RD would not move. The shifters (up or down) would sometimes just move and not engage, and other times would click. But no RD motion at all.

I rode home and took a closer look (not a mechanical type and I wasn't sure how to even open up the shifters - looks like you just roll back the hood covers). I noticed that on the right side that little 'push pin' that Campy provides (moves the end stop for the brakes and basically will open up the brakes calipers a tad) was stuck. It just would not move. I could not imagine what this little push pin in a holder would have to do with the RD cable/indexing, but I got out a pair of pliers and VERY carefully pushed harder on this pin. It now is shifting fine (brake push pin and the RD). I had just pushed the up/down shift controls 50 times with zero movement. Force open that little push pin and all is fine.

Then went for a 35 mile ride today with no shifting issues. Two other comments.

1) I think that I have encountered this a couple times before where, at the start of the ride (just like this time) , I have tried to do a RD shift and nothing happened. But it always worked the second time (IIRC). I blamed this on #2 below (when it happened it isn't like I was paying close attention)

2) I am at roughly end of life of my chain (new chain on the way).

The was an LBS purchase/install so warranty service (if required) should not be a problem. But I wonder if anyone has an idea of what happened here other than maybe some piece of grit in the shifter that got dislodged when when I forced open the brake push pin (and I didn't really force it that hard - but harder than I could comfortably push with my thumb).

Thanks.

dave

CafeVelo

I had that happen shortly before the return spring for the paddle broke. Basically what's happening is the escapement on the paddle isn't disengaging properly, which locks out the thumb lever. The inside of an ultra shift lever is really simple, it's basically a friction shifter spool on an axle with two ratcheting adjusters (the thumb lever and paddle) that move one way and don't engage when it moves the other direction. If one of them locks out or that direction is otherwise immobilized, then the shifter locks because the ratchet is jammed. Grit, lube failure, spring slip or breakage, overtight pivots, an overly tightened main screw on the shifter axle itself, an undertightened main screw, and even a fraying cable head could cause this symptom.

DaveLeeNC

Thanks, Cafe. I'm still not sure what the issue is/was but I will add another suspect to the list. From what I see it would be very easy for the rubber hood covers to interfere with the motion of the shifter. It is REALLY close to where the thumb lever meets the wratchet, from what I can see.

dave