Any tips on this? It happens when I'm shifting from the little to big ring on the front derailleur. The chain comes off (over the front ring) or has trouble finding the front ring. I had 2 bike shops adjust the limit screws and changed the chain. This is much more likely to happen when I'm in the middle of the cassette on the back (front derailleur shifting much smoother when chain is on the easiest first or second gear in the back-harsher from the third, and worse from there).

I'm running shimano 105 10 speed (2014 version).

Thanks!

Lets say your cable, shifter and parts are in good shape.

So it starts with position of the FD. The bottom of the cage should be no higher than a nickel width off the big ring when lined up. Easiest to set up a FD with the chain and cable off.
If your shop has played around with the limit screws but haven't touched the position of the FD, that is where I would start.

Not sure why limit screws would help. They serve to keep the derailleur from going too far inboard and outboard.

It's either the cable tension, or as Campa4life suggested, the position of the FD.

I think OP mentioned that chain was coming off -- being thrown outboard over the big ring.
Yes to cable tension (have cables been replaced since 2014? install of the groupset?), and possible FD height above the big ring -- check this with crankarms parallel with the ground, as the teeth height I think varies by where they are on the ring relative to the crankarm.

Also, FWIW, 5700 left shifter shifts like crap anyway, even when set up properly.

Mine seems fine. Only issue I've ever had was simple cable stretch.

The 7900's were the first Shimano shifters to have the cable under the hoods. The left shifter on the 7900 works okay, perhaps better material. But I've got two 5700's and both front shifters are nowhere near as smooth and buttery as the previous gen with the cables coming out of the side. Can't speak for newest generation 5800's, but I hear the front shifts much better.

plus 1 on the derrailleur positioning.

Is the cage parallel to the chain ring?

Thanks Campag4life, I will attempt to adjust. I haven't moved it since I got it, and the shifting used to be crisp-is slippage a common issue?

Hi, correct, the chain often goes over the front ring when shifting into the big ring. I haven't changed my cables ever (6000 miles approx on them with lots of shifting-SF bay area riding). Maybe getting a high grade tune up and cable replacement is the best call (worried about doing the cables on my own).

Why are you worried? It can be a bit fiddly to thread the cable into the shifter but it is not exactly hard.

I had the same issue earlier this summer (also on 5700). A new cable cleared it right up It was a much easier repair than I expected.

I'm not very mechanically inclined and don't want to make it worse. I would really like to learn though-I'll probably give it a shot.

Thanks Wipekitty, I'll give it a shot.

It's a CAAD10 and this version has the shifter cables external to the frame (brakes are internal though). Trying to avoid the walk of shame to the bike shop with undone cables-been there once!

Good for you! I am not very good with mechanical things either, but Bicycle bits can usually be figured out by working the mechanisms and watching how things move. Eventually things click (in your brain!) and you can see how it works.

This. If the front derailleur cage is not parallel, specifically closer to the frame at the rear than the front, then the shifting impetus is not as firm as it should be, which results in the chain having to "climb" over the big ring, which sometimes takes a couple of revolutions to catch. A real easy adjustment to make as well.

It seems I can't touch cables of any kind without fraying them. I have little metal strands poking out now like tiny hairs from the old cable. Is there a trick to this? Frustrated and discouraged. I tried changing brake calipers as a test project before tackling the shifter cable and failed at that miserably too.

I'd pay good money for a bike mechanic to watch me take my bike apart and put it back together, and provide guidance along the way. Is this something bike mechanics offer in their off-time? SF bay area.

Old cables fray easily, new ones much less so. Look for bike maintenance clinics in your area. Until then, have a shop change out your cables.