I started riding a lot back in May (200 miles/week anyway). Campy Chorus (2014) groupset, BTW.

Most of the time a dropped chain is a rare occurrence. But for the 2nd time now I find myself dropping a chain (when going from the big ring to the little ring) on about half my rides. This lasted a week or two a couple months ago and then it just completely stopped. There never was an obvious adjustment to be done here and it was never clear why it stopped (or started).

Suddenly, after not having dropped a chain in at least a month I have hit 3 of them in the past 10 days. I am guessing that it is shifting habits. It is pretty much always when going from big to small chainring when headed up an incline. My habit when hitting a rise in the big ring that needs the small ring (particularly when coming off a decline) is to pick the RD gear that I want to end up in, and pedal there on the big ring down to 65 or so rpm. Small pause while I shift the FD, and off I go (or not if the chain got dropped). Always to the inside, BTW.

I am guessing that I just need to be more cautious and careful in 'the pause' and not be so quick to resume pedaling. Or maybe it is something completely different.

THoughts/comments? Thanks.

dave

Adjust your limit screws, cable tension, and install a chain catcher

if the final rear gear you want is in the final 2-3 cogs and the chain is cross chained before the front shift, this will often cause a drop. My suggestion is to shift earlier to the small ring and then shift to the final gear you want in the rear progressively.

I'd change out my rings. It's dropping with a load on the ring, meaning that load is a contributor, meaning that the ring is worn or burred or both.

Chain catcher as a backup to better shifting technique and precise adjustments. The catcher is not bad looking; it's light and not terribly expensive. Why not?

+1.

I've had a similar issue lately. Same place each time. I also have campy. Record front, chorus rear. There's a small bridge I cross frequently and I always start from a standstill. Of course, I never think to shift before I stop and I'll shift the front and back simultaneously once I get on the bridge. I can shift that way with no issues anywhere except this bridge. It always drops the chain there. Must be haunted or something.

Adjust your FD inside stop to just barely clear the chain when in the small front-big rear combo. Maybe even rub a touch. Check to make sure it still shifts quickly. This may take a few tries to get it dialed in to get the FD cage as far out as possible and still shift. Then try to be mindful that when in you biggest cogs, you have to shift gently, ie little to no pressure on the pedals. (Remember the famous incident of Andy Schleck derailing at the Tour de France, also derailing his chance to win? That is a good lesson in how not to shift.) As said above - chain guides are cheap, light and work quite well.

Thanks for all the comments.

After thinking about this it occurs to me that I USUALLY am not on the larger sprockets when I shift down to the small ring (I typically do some RD shifting before the big-small shift). But USUALLY I don't drop a chain. I would not be at all surprised to find that every chain drop that I have encountered happened when doing a FD shift in the larger rear sprockets. So caution there is step #1 .

dave

I used to run a compact crankset with a standard derailleur and had that problem quite frequently. This worked a treat.