Shifting problems w/new compact crankset

[jenxxs]

OK, thanks for these suggestions about the limit screws. I think I am going to get a second opinion about the current derailleur setup. From what I've read so far, I should be able to get my standard Ultegra derailleur to work if set up carefully.

[Triskeliongirl]

My advice is to learn how to make these simple adjustments yourself. I got so sick of bringing my bike somewhere, waiting for them to work on it, picking it up, and paying good money only to have these kinds of problems. Just pick up a good book (like Zinn's road bike maintenance) and use web resources like the park tool website and sheldon brown website. I will tell you that in my hands the compact derailleurs worked better than the ultegra since the ultegra is designed to go from a 52 to 42 or 39 not a 48 to 34. For me, an old mountain derailleur also designed for smaller rings worked better, but I also had to deal with the elliptical shape.

[mimitabby]

our tandem (which needs a new bottom bracket) also drops its chain far too often. We bought this little hook-looking thing which is supposed to catch the chain and bounce it back to where it belongs. It doesn't really work very good, and sometimes the chain gets stuck underneath it or behind it or whatever.

the reverse shifting does work unlesss you have slowed down too far and have lost momentum. But when it happens, it always feels magical to me.

[Kalidurga]

We bought this little hook-looking thing which is supposed to catch the chain and bounce it back to where it belongs. It doesn't really work very good, and sometimes the chain gets stuck underneath it or behind it or whatever.

My bike came with a chain catcher (the little hook-looking thing), but it wasn't installed correctly in relation to the small ring. I complained about chain droppage and the LBS tech realized that the Dog Fang wasn't low enough or close enough to the ring to actually keep the chain in place. It needs to be right at the level of the chain on the small ring, and only a couple of milimeters from the chain. Try moving it so that you can just slip a penny or nickel in between the chain catcher and the chain on the ring.

My bike also came with a 48/34 and I've had major issues with shifting up to the big ring. The inside of my ring is all scraped up from the number of times the chain has rubbed against the ring as I've pushed the shifter and cussed at it to go. After having three different LBS tech's play with it, I finally had to give it a try myself. Once I realized how the limit screws work, it really was easy. You just need to make sure that you check any adjustments on both rings, which is a mistake one of the LBS guys made. He adjusted it to make shifting onto the big ring easier, but then the chain rubbed against the derailleur when on the small ring. On my ride that afternoon, I was forced to sit on the side of the trail and put to use what little I had read about derailleur adjustment. I've had no problems with it since (*fingers crossed*.

[7rider]

I have an FSA compact crank on my bike (a 50-34).
When I had it installed, I had the shop put on the chain-keeper (is it a.k.a. "Anti-chain suck thang"? I seem to recall having that name in my head when I asked the shop for it. They knew what I was talking about at any rate.) I have no problem whatsoever with the chain dropping when going from the big to small ring (FWIW, it's a FSA SLK crank with a Dura Ace derailleur). Don't know if the keeper saves me, or if my bike is just adjusted okay. Maybe a bit of both?
Where I DO have problems is throwing the chain clear OFF the big ring of the crank and onto the crank arms when shifting up. That, however is "user error." I've learned to (1) be mindful of where my chain is on the cassette in back, as that has a bearing - centered is better), and (2) use a light touch. The DA shifters require a subtle touch, not the mashing I am used to giving.