[Dale Brigham]

Greetings:

I'm feeling beaten down this afternoon after having failed to figure out how to make an FSA compact front derailleur work on my Steelman. I run an FSA compact crank, and after a couple of years of non-perfect shifting with a Shimano Ultegra front derailleur (occassional chain deraillments off both the outer and inner rings, along with persnickity trimming), I thought I'd give the FSA a try. After an hour or so of trying every front derailleur trick I know, I was unable to get it to reliably shift up/down across all of the the cogset (9-speed) variations on the stand, which usually predicts bad things on the road. I tried positioning it higher and lower on the seat tube and rotating it inward and outward. Of course, I also monkeyed around with the limit screws until I gave up. I put the Ultegra back on the bike, and, after a couple of adjustments, it shifts like a champ (at least on the stand) compared to the FSA.

There is one thing that could be the problem: I am using non-FSA chainrings on the crank. I put Stronglight rings (48/36) that I had on hand on the FSA crank to see if I like that tooth combo better that the standard 50/34 configuration (I do). They may have different offset/spacing than the FSA ones. Just for the record, the front shifters on my bike are friction bar-cons, so indexing is not the issue.

The FSA front derailleur is very nice looking and seems to have top quality materials and design. I'm not impugning their product; I'm just frustrated that it did not work in my hands. Any and all hints and suggestions would be greatly appreciated.

Best Regards,

Dale

 

[winstonc]

The FSA derailleur is designed for a 16 tooth difference between the chainrings, while the Ultegra (9-speed, I assume) is designed for a 14 tooth difference. Since you're usng chainrings that are 12 teeth apart, that may explain why the Ultegra works better, and also why it's still not perfect.

If you're getting derailments off the inside and outside of the rings, maybe your limit screws need to be tweaked?

 

[Dale Brigham]

Limit screws and chainring tooth differences

winstonc:

Yes, the 12 tooth chainring difference (48/36) could have bamboozled the FSA, which, as you rightly point out, was designed for a 16 tooth chainring difference (50/34). Regarding your comment on the limit screws, alas, the limit screws on the Ultegra had been set up as to rub on the chain slightly on both the innermost (36/26) and outermost (48/12) combos, which pretty much limits how much you can keep the chain from going off the rings. It did that on both the 50/34 and the 48/36 setups, but was a bit worse on the latter. However, I must admit, I had not lowered the Ultegra the prerequisite 4 mm I should have after I changed from the 50 to the 48 tooth outer chainring. Pure laziness on my part. Properly adjusted, the Ultegra seems to work just fine.

Thanks for your constructive comments.

Dale