What’s wrong with my FD setup?

[kookmyers]

My chain is getting outside my FD. My crank arm is also scratched. Started happening when I changed my crank from standard to compact. I moved the FD to what I thought was the right spot and shortened the chain at that time.

[tuscanyswe]

Looks like a clamp on fd right?

Is it slipping down the seattube? If to low it can certainly rub on the inside arm.

The height kinda looks good in the pic but hard to tell as its on the small ring.

[Peter P.]

Your large chainring teeth look worn.

Notice the slope on the right hand side of each "U" versus the left. The sides should be symmetrical.

[David Kirk]

So - when you shift from the small to big ring it shifts past the big ring and falls off the outside?

dave

[dddd]

I can't tell the meaning of the chain getting outside of the front derailer.

Unless the chain or cage is broken through?

Did you mean the chain overshifting the big ring and scratching the crankarm?
I hate when that happens.

Perhaps another photo from the top, showing the big ring (hi) derailer position.

The hi limit screw should allow just a skosh more travel beyond the indexed hi-position detent, but not much or the chain may fly over the big ring. The chain should almost touch the inside of the outer cage plate when you are in top gear (tallest gear), just as the chain should almost touch the inner cage plate when you are in your bottom gear.

I like to set up these Campagnolo drivetrains using just the cable adjuster and lo-limit screw first, then set the hi-limit screw to finish the job. This way the detent positions are exactly where they are needed, and the hi-limit screw isn't preventing free access to the last detent in the direction of the big ring.

Your derailer's height and angle both look just right to me.

[John H.]

Agree on the rings- they are worn.

Did you change chain length? Or leave the same?

[Geekonbike]

Shark tooth Front Chainrings will let the chain jump off on an otherwise properly adjusted front derailleur. But I'd try to futz with the derail limit screw first.

[kookmyers]

Originally Posted by tuscanyswe

Looks like a clamp on fd right?

Is it slipping down the seattube? If to low it can certainly rub on the inside arm.

The height kinda looks good in the pic but hard to tell as its on the small ring.

I don’t think it’s slipping down. Yes, it’s a clamp.

Originally Posted by David Kirk

So - when you shift from the small to big ring it shifts past the big ring and falls off the outside?

dave

it doesn’t fall out completely. I have had 3 instances now when I shift and my drivetrain locks up, the chain is smashed in the FD and crank. I’ve learned that gently rocking the crank back and forth gets me going again.

Originally Posted by John H.

Agree on the rings- they are worn.

Did you change chain length? Or leave the same?

. I did shorten the chain.

Sorry, I am not sure how to answer everyone’s questions efficiently. I hope this works.

So, my rings are worn and that has caused this mess? Bummer.

[Kontact]

The FD could be lower.

I've seen inner abrasion plates on Campy carbon derailleurs break off causing upshift issues. Make sure all of the derailleur is intact.

[josephr]

I can't tell if its the picture angle but it looks to me like there's a warp of the big chain-ring...with each missed shift, then its bending it a bit more with each jam. If its not been having this problem before, then I'm going to say the FD adjustment is probably fine, and its time for a new set of chain-rings. That's my $.02.

[booglebug]

Had this same issue that drove me nuts. Replaced chain,cable and housing and still had the same problem with jamming and over shifting, the over shift was due me thinking that the limit screw was not letting the derailleur move far enough and adjusting the screw to far. Finally came to the conclusion it had to be in the shifter so removed only to find the back screw was loose ( the screw in the back once the clamp is removed) tightened and problems solved.

[spoonrobot]

The chainring teeth are not worn nearly enough to cause this issue - I would estimate you're barely 1/3 of the way through the life of that chainring, if that.

It's a height/limit issue and may be related to chain length as well.

[eddief]

is that FD cable attached and threaded behind the fixing bolt in exactly the correct way? if like Shimano you sort of have to get it under an outcropping before tightening behind the bolt. Looks like you might have missed the outcropping.

[lhuerta]

...still not clear, Is chain jumping off big ring? Where/how is it getting stuck between frt der and crank? If it’s overshooting big ring when u shift from small to big then sounds like a limit screw adjustment and if it’s dropping when u shift from big to small then its likely the same thing, given that height and alignment appear OK. Big ring is definitely worn. Share pic of chain in big/big? Also what cog are u in when it jumps?

[JDino]

+1 on the chainring issue...but here's my 2 cents

Replace both chainrings and replace the chain...wear parts should wear together. Also, look at the cassette and see if that needs replacing too, which it probably does based on the wear on the rings.

The FD setup looks okay. The space between the bottom of the FD cage and the top of the big ring teeth should fit the width of a penny and maybe a tiny bit more. Also, just double check that the cage is parallel with the chainrings.