I'm running a 5800 105 setup and when the bike is on the stand at home it shifts crisply. I run a compact double, and when my 205lb behind is out riding I can shift from big ring to small ring with ease, but shifting from small to big is impossible. Usually I'm going downhill or on a flat road spinning at 80-100 rpms and when I try to shift into the big ring I hear what sounds like the FD moving the chain but it keeps dropping it and it falls back on the small ring. If I get off the bike and lift up my rear wheel it will shift without any issues. Would a chain catcher fix this? Also, why would this issue suddenly develop? I was about 10lbs heavier a couple months ago and I never had this issue.

Your cable stretched. Readjust your front mech.

I've had good luck when upgrading the front deraileur. In the past, the higher end deraileurs, Dura Ace(maybe even Ultegra) had tighter tolerances. I'd first have your setup looked at. Maybe your trim screw just needs a little adjustment.

Take off the load , get ahead of the gear, to let the shifting work.

. One should be able to shift even with load.

.. good luck with your reality then..

Ive always read the terrain and chosen the gear I needed early, not Late.




If it wont go with a smaller force get a bigger hammer

Yeah, what ^ said. +1 (Which goes a long way towards explaining why something works on the stand but not on the road.)

But you also need to check your front derailleur alignment. Front changers are very sensitive to cage alignment issues so make sure the outside cage plate is aligned with the large chainring.

You should also give the high limit screw (that the one that lets the front mechanism move out) a 1/8 turn counter clockwise. Test it on the road. If necessary add another 1/8th turn CC direction. Go slow with your changes, you want it just right.

C̶a̶b̶l̶e̶ ̶s̶t̶r̶e̶t̶c̶h̶ ̶s̶h̶o̶u̶l̶d̶ ̶h̶a̶v̶e̶ ̶n̶o̶ ̶i̶m̶p̶a̶c̶t̶ ̶o̶n̶ ̶t̶h̶i̶s̶ ̶s̶h̶i̶f̶t̶.̶ ̶T̶h̶e̶r̶e̶ ̶w̶o̶u̶l̶d̶ ̶n̶e̶e̶d̶ ̶t̶o̶ ̶b̶e̶ ̶t̶o̶o̶ ̶m̶u̶c̶h̶ ̶t̶e̶n̶s̶i̶o̶n̶ ̶o̶n̶ ̶c̶a̶b̶l̶e̶,̶ ̶n̶o̶t̶ ̶t̶o̶o̶ ̶l̶i̶t̶t̶l̶e̶,̶ ̶b̶u̶t̶ ̶t̶h̶e̶ ̶e̶x̶t̶r̶a̶ ̶t̶e̶n̶s̶i̶o̶n̶ ̶m̶i̶g̶h̶t̶ ̶k̶e̶e̶p̶ ̶t̶h̶e̶ ̶d̶e̶r̶a̶i̶l̶l̶e̶u̶r̶ ̶f̶r̶o̶m̶ ̶r̶e̶a̶c̶h̶i̶n̶g̶ ̶i̶t̶'̶s̶ ̶m̶a̶x̶i̶m̶u̶m̶ ̶"̶s̶h̶i̶f̶t̶"̶.̶

Don't know what I was thinking. here.

Huh?

Shifting is like voting in Chicago; shift early, shift often.

Shift before you need to shift, soft pedal while shifting. The reason your bike shift well on the stand is because there is no load on the drivetrain. Add the load, ie. your pedaling hard, and shifting gos down the tubes.
On your next ride, try shifting as you do normally, and try shifting while soft pedaling(no load). See what happens, report back.

Tried this already. Even soft pedaling doesn't work. I had a brief moment of reprieve when I heard the FD struggling to shift and I stopped pedaling momentarily and then started soft pedaling and it actually shifted. Tried it again a few times and couldn't reproduce the results.

Thanks for the suggestions so far. I'll do a bit more investigation and fiddling and report back.

Inspect the cable inside of the brifter (and elsewhere) and make sure that it has not begun to fray. If so replace it immediately. You do not want to have to dig the broken-off head out, MUCH easier to fix it before it breaks off. Always check this when a sudden change in shifting is noticed.

It could be three things (from my own experience)

The cable tension could be too loose - check to see if when you shift to the big ring if the derailleur even hits onto the stop bolt. If it doesn't, tighten the cable.

The stop could be out of adjustment - If the derailleur is indeed hitting the stop, back it out 1/4 turn at a time and see if that helps.

The alignment could be off. Sure, we all know the cage is supposed to be parallel with the chain rings. But parallel can actually be hard to judge and at best is inexact - poor lighting, poor eyesight, imperfect cage surfaces to judge by. Or exactly parallel might not be exactly best.

So don't get totally hung up on "parallel". You might not actually have it parallel, or parallel might not work perfectly.

Frankly, I set it as parallel as I can get, and if it doesn't work properly going onto the big ring, (after checking the above two), I tweak it a tiny bit to where the cage might be angling outward a tiny bit. Tiny. For all I know - because of poor lighting and poor eyesight - the new position could actually now be truly parallel.... or it could be angled out a tiny bit. I don't care if it works.

Like others said, some finesse might be needed for front shifting. It's night and day better under load-ish situations than it was 40 years ago though. Still, I try not to shift when I'm grunting on the pedals. "Feathering" the upshift you might call it.

Some technique is required for front shifting (compared to rear) but it should still work. A 105 FD should work just fine, an upgrade is not the solution. Check these things, in this order:

- Cage position. Too far from the rings? Not the correct angle?
- Cable tension. Cable tension could be too loose and not pulling the cage far enough to get into the big ring.
- High limit screw. High limit screw could be in too far not allowing the cage to move far enough to the big ring. Generally you "overshift" just a little to get into the big ring and then the FD settles back to it's normal position. Not allowing this overshift could be causing your issue.

Do not bother messing with the low limit screw as it only affects shifting and running in the little ring.

Plenty of bikes have enough flex to turn perfect shifting on the stand into not great shifting on the road. Of course check the tension, limit screws and such as directed above and also realize that you still may have to do a final tweak after adjusting it on the stand but at that point it should be a minor tightening via the adjustment barrel.

This was my first thought; try backing the high gear stop out a bit, maybe 1/4 turn to start.

Of course, if your cable has indeed stretched as was suggested you will need to take up that slack as well...

If you're having this shifting problem going downhill, how much load are you putting on it? I can see problems due to load if you're late in shifting while going uphill, but going downhill? That sounds like an adjustment problem more than a technique problem. Of course, I'm fat and lazy and take it easy on downhills.

So I fiddled with the barrel adjuster and now it shifts into the front ring while under load, albeit not as smooth as it used to. I just took it for a quick spin around the block so I didn't have any significant downhill stretch of road to test out the shifting while soft pedaling. As usual, shifts are crisp on the stand. The only issue is that I seemed to have lost the lower trim position on the small ring, so now I have the outer and inner positions on the big ring but only the outer position on the little ring.

If your FD cable was highly tensioned in the big ring and the FD frame clamp was not quite tight enough, the derailleur may have slipped around on the frame and angle may have changed. Check FD in the big front small rear combo - chain should be in line with the outer cage.

Thank you all for your insight contributions to this thread. I've finally gotten things back to "status quo", so to speak and it was the result of these two issues. Loosening the high limit screw in addition to fiddling with the barrel adjuster has brought back crisp front shifting "under load". I'm just a bit perplexed as I had previously thought that limit screws were something that you set and forget, and not necessarily part of the fine tuning process. Thanks again!

My first shot would be to dial out the high limit screw about 1/8 turn.

They are "set it and forget it" in the sense that you should never have to adjust them if they were done right the first time. But they do play a big factor in proper shifting and need to be fine tuned just right.

The reason they are often mentioned as "don't mess with the limit screws!" is that newbies will often start cranking on them trying to improve shifting when they're almost never the culprit, throwing everything way out of whack. The most severe danger is backing out the low limit screw on the RD enough so that it can be shifted into the spokes, potentially destroying the RD, rear wheel, and possibly even the frame all in one shot.