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Front derailleur adjustment question(5 posts)

Front derailleur adjustment questiontad
Jul 30, 2002 7:12 PM
I adjusted my front derailleur according to the maintenance book I have (2 mm clearance on inner and outer positions). It shifts fine between the big and little ring. However, when I go from little ring to big ring, I get a chain rubbing noise until I tap (trim?) the front shifter. I didn't have to do this in the past. Why now? Is that how it's supposed to work? I'd rather not have to do this! Thanks.
DuraAce shifters (forgot to mention in case that matters)tad
Jul 30, 2002 7:13 PM
re: Front derailleur adjustment questioncurlybike
Jul 30, 2002 7:21 PM
The outer cage of the front der. may not be parallel with the big chain ring, generally, it should be.. Sometimes you can tweak the position of the der. to avoid trim requirements. You should adjust the upper and lower limits so that the der. barely misses rubbing in the extremities of chain angle. The cage should just clear the big ring vertically.
The problem is your left barrel trim.Paul
Jul 31, 2002 3:19 AM
This is a little tricky to set up as it will move your der. in one direction or another. You didn't say where the rub was coming from (little to big). This has nothing to do with Ultegra or Dura Ace. I normally set the barrel to the mid-point before I adjust the der. clearances. You can try this: shift to small chain ring, adjust barrel in a CCW (couple of turns), this brings der. inner cage closer to chain, CW moves it away. You might luck out with just a couple of turns. Be careful, as this can also affect your der. throw.

If this doesn't work, start from scratch. Make sure you have shifted to small chain ring/large cog when starting. Instructions talk about trim.
re: Front derailleur adjustmentChen2
Jul 31, 2002 5:52 AM
Sounds like you don't have enugh tension on the cable. And you may need a new cable if it is more than 2 years old. Shift to the smaller chain ring. turn the barrel adjuster most of the way in (clockwise). Lossen the cable at the derailleur. Pull out the cable slack and re-tighten the retention screw while holding the cable with no slack. Try shifting and adjust the barrel adjustor as needed. Sometimes new cables and housings can put new life into a bike.