Weird SRAM front derailler problem
 

Started this thread in the mechanics forum but not many answers there. Will post here for more eyes to see...

I have the Apex 2x10 components and the front derailler is giving me issues. It shift okay, not the best, going from the small to large ring while on the repair stand but once I take it out on the road it fails to shift to the big ring. All adjustments looks and works fine, components don't seem to be worn or anything. I also have a new chain. I was wondering if maybe the chain ring, derailler or shifter is going bad but cannot pinpoint the problem.

Anyone here experienced this issue before? I know SRAM FD have been know to be iffy but I need a place to look before I start replacing parts. TIA...

I have SRAM Red and have had a similar issue. With mine it was the angle of the derailleur. It took someone who also rides and knows SRAM to fix it. Drove me crazy because it didn't consistently misbehave.

Look down at it from above when it's on the big ring and it should be exactly parallel to the big ring. If it isn't then put it into the small ring again and adjust the position at the frame clamp.

Can you increase the tension by turning the cable barrel adjuster counter-clockwise a few clicks? If not you might need to put it into the small ring and then take up some cable slack. Mark the cable at the adjustment bolt with a sharpie pen and pull out the cable another half millimeter. On the small ring the cable should be taut but not under tension.

Ooooh, a hint... Can you define "angle of the derailleur"? Can it bent back into shape or something? Maybe best to get a new FD??? Yeah, mine is inconsistent also but fails most of the time. Will look closely and see if its bent or something... Thanks

You might have the cable tension too high. To test this, with the chain on the big ring push the shift lever a little bit (ie, first click), does the front derailleur move a little bit inward yet still remain on the big ring? If not, the tension is too high.

Just general setup advice.
1. set outer plate parallel with outer chainring via mounting bolts.
2. set clearance between top of teeth on large ring to cage at 1-3 mm.
3. set limit screw so that you can go a little past the big ring's index.

This is how I understand it. The FD needs to be parallel to the frame. It's probably not bent but I'd have someone who knows check it out.

I'm betting you have the derailler cable running the wrong way. I had the exact same issue you describe on an apex front derailler. I had never had SRAM before so ended up taking it to the shop because i couldn't figure out the problem - they disconnected the cable, moved it so it routed up over the anchor bolt from the other side, and it worked fine.

Maybe a silly question, but you are easing up on the pedals (still spinning, but less tension on the chain) when shifting the front?

There's a little groove in the cable clamp area. In order to index properly the cable has to be in the groove. If the cable is 'off,' then it might not shift far enough to move the chain to the big ring while under slight load. Just a guess.

This is why SRAM has said the "front derailleur is dead" not because it is dead and 1x is the best thing ever for everyone but because they are terrible at making a good front derailleur.

Many of the posts already provided great advice. Checking the alignment of the derailleur would be the first place but also checking limits and tension but I know with a lot of modern derailleurs they are oddly routed cable wise and that can cause problems, Shimano has done that recently with some of their stuff.

I was having much the same issue with my Rival FD. Using Force 2x10 brifters and Red crankset. I can say I think I finally got it working OK, enough that it doesn't drop the chain or overshift. But it certainly doesn't like to shift under load. I fussed with it for weeks. Preferring to take my other bike for rides instead...

I feel better that I am not the only one with this issue...

I finally think I found the right combination to deal with this problem. I'm not a 100% satisfied but at least I got it to work okay like mentioned above. It seems that the shift happens in a very narrow window under the right circumstances. Steps used were as follows: back out the high limit screw a bit 2) tighten the tension of the cable 3) slightly squeezed the inner and outer plates surrounding the chain about 1mm or so (not advised but I did it anyway so that the chain doesn't drop off the crank) 3) readjusted the limit screw 4) stop pedaling, shift to big ring, then start to pedal slowly till in gear.

The last step seems to be the key for whatever reason. It shouldn't be this way but that's the way it is. I'm not racing or anything so it doesn't matter too much but it sure is annoying. I'm already planning to maybe switch over to the Shimano camp soon but in the meantime will deal with what I have for now. The more irritated I get the faster I will switch...

That's not been my experience. I really like my SRAM Force groupset. The 'Yaw' on the front derailleur works really well meaning I can run every ratio without the chain rubbing on the derailleur. I don't think I'd want 1x on a road bike, though I can see how it makes sense on a mountain bike.

Just a note re: angle of derailleur - the Red has Yaw and the Apex doesn't, which makes the setup different. Setting up Red and Force derailleurs is different to the traditional way where you just set the cage parallel to the chainset.

There's no reason or rationalization I can think of that would require you to stop pedaling; but it's a known 'problem' with all front derailleurs that they have varying levels of working terrible when the chain is under load. Also, and I don't know if it's been mentioned here; but derailleurs have 'shift ramps' too. The ones that will work best for you are the ones designed specifically for your chainring combinations. I have a D/A triple FD that absolutely cannot shift a 30/39/53 but works fine for a 30/40/52.