Derailleur adjustment with compact crank

[HillSlugger]

I bought a used bike and switched it from a standard crank to a compact crank but I'm having a devil of a time getting the front derailleur properly adjusted. I'm constantly dropping the chain to the outside when I shift from small to large. If I back off the limit I can't get onto the large ring!

Is there an Ultegra level derailleur designed to work with a 50/34 crank?

I love my bike but I was so frustrated today I was ready to throw it into a ditch! Please help me preserve this love affair!

[Becky]

I'm running a similar set up, and recall that it was a bit fickle to set up. IME, FDs on compacts seem to be more touchy about cable tension, even if the limit screws are correct.

Have you lowered the FD to compensate for the smaller outer ring? What FD are you using now?

Good luck, and don't give up- it will be worth it in the end!

[HillSlugger]

I'm running a similar set up, and recall that it was a bit fickle to set up. IME, FDs on compacts seem to be more touchy about cable tension, even if the limit screws are correct.

Have you lowered the FD to compensate for the smaller outer ring? What FD are you using now?

Good luck, and don't give up- it will be worth it in the end!

It's currently got an Ultegra FD (not sure of model). Yes, I lowered it when I first made the switch and I monkey with it again when trying to get it better adjusted. It worked flawlessly last weekend; this weekend I was ready to trash it. I can't help but think it would be working better if the curve of the FD were better matched to the curve of the large ring but I can't seem to find something like this.

[7rider]

I'm not sure about Ultegra, but I know Dura Ace can. If DA can, I would presume Ultegra can.
What kind of crankset do you have?
I have a FSA compact on the Axiom with a DA FD, and I was constantly throwing the chain off the crank. The mechanic at the LBS, who spent lots of time adjusting it, attributes it to USER ERROR! Yes, you MUST be very careful about where your chain is on the cassette (mid cassette is best) and not heave the shifter too much. Just a soft touch. It took me a while to learn the technique. I am really good with the user error problems!
That said...
My ID8 has a Shimano Ultegra compact crankset and Shimano FD (also DA) and I have had no trouble whatsoever with throwing the chain.

[HillSlugger]

Last week I was able to shift it without thinking about it; today I had to be so careful my shifts were taking forever!

[HillSlugger]

I want to race on this bike in just a few weeks and I want to feel confident that when I shift I won't end up on the side of the road fixing my chain!

[7rider]

I want to race on this bike in just a few weeks and I want to feel confident that when I shift I won't end up on the side of the road fixing my chain!

Do you have time next weekend to do some HoCo hills with me? We can run it through its paces and see what's up....

[HillSlugger]

Anyone have experience with the FSA Gossamer FD? It says it's specifically designed for compact cranks.

[Cataboo]

I've got ultegra shifters, front derailleur, & am running a 50-34 crank without a problem. It did ocassionally go off the inner chainring when i first got it, told the bf to tweak it, he spent about 5 mins, and it's been fine ever since.... I can force it off if I'm dumb and don't realize that I'm in the big chain ring and I keep trying to shift into it (I dunno why, but I did that the other day)

Bf's also got the same set up on one of his bikes (ultegra and compact cranks), so it can be done and it didn't seem particularly difficult to do.


What cranks are you using? I know in some of the crank reviews I've been reading (fsa gossamers), people have claimed that buying shimano compact cranks completely solved any problems they had with tuning the compact or the chain going off the cranks...

[HillSlugger]

I've got ultegra shifters, front derailleur, & am running a 50-34 crank without a problem. It did ocassionally go off the inner chainring when i first got it, told the bf to tweak it, he spent about 5 mins, and it's been fine ever since.... I can force it off if I'm dumb and don't realize that I'm in the big chain ring and I keep trying to shift into it (I dunno why, but I did that the other day)

Bf's also got the same set up on one of his bikes (ultegra and compact cranks), so it can be done and it didn't seem particularly difficult to do.


What cranks are you using? I know in some of the crank reviews I've been reading (fsa gossamers), people have claimed that buying shimano compact cranks completely solved any problems they had with tuning the compact or the chain going off the cranks...

Not Gossamers, FSA Pro cranks. I'd rather change the FD than the cranks if it would help. I'm thinking seriously about the FSA Gossamer FD.

[7rider]

I know in some of the crank reviews I've been reading (fsa gossamers), people have claimed that buying shimano compact cranks completely solved any problems they had with tuning the compact or the chain going off the cranks...

That was my experience.
FSA (SLK) crank + Shimano FD = chain off the crank upon shifting (okay..not CONSTANTLY...but often).
Shimano crank + Shimano FD = no shifting issues.
Cannot speak to FSA crank + FSA FD.

[lunacycles]

Front derailleurs specifically designed to work with compact cranks are usually put into use to help prevent dropping the chain to the inside of the small ring due to the big differential between c-ring sizes...not the issue you are having. I would recommend checking the angle of the cage over the big chainring, and make sure it is exactly parallel, also that the FD sits only about 1mm above the chainring teeth (i.e., as close as possible).
I run an FSA compact crank with Ultegra FD and have zero problems.

[Cataboo]

That was my experience.
FSA (SLK) crank + Shimano FD = chain off the crank upon shifting (okay..not CONSTANTLY...but often).
Shimano crank + Shimano FD = no shifting issues.
Cannot speak to FSA crank + FSA FD.

I'm using an FSA crank with ultegra front derailleur. The chain mostly doesn't go off the crank, but it does happen occasionally.

[HillSlugger]

Front derailleurs specifically designed to work with compact cranks are usually put into use to help prevent dropping the chain to the inside of the small ring due to the big differential between c-ring sizes...not the issue you are having. I would recommend checking the angle of the cage over the big chainring, and make sure it is exactly parallel, also that the FD sits only about 1mm above the chainring teeth (i.e., as close as possible).
I run an FSA compact crank with Ultegra FD and have zero problems.

Margo, thanks for the insight.

Because the curve of the FD doesn't match the curve of the 50T ring the spacing between FD and crank varies at all points. I know I can't lower it any more or the chain can't get onto the big ring.

With a braze-on FD how much adjustment do I have for parallel? Should I give this another try on my own or drop it off at the LBS and hope they can work some magic? Why did it work perfectly last week but fail me yesterday?

[lunacycles]

With a braze-on FD how much adjustment do I have for parallel?

You should have some. Often the derailleur and the braze on fall in love in a certain position, but if you hold the derailleur firmly in the alternative, more ideal position, it should move a bit for you. Definitely try it again...what have you got to lose? Derailleur adjustment stuff tends to be finicky more often than not, and so often requires patience and at least a few tries til you find the sweet spot. Good luck.