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I have the dura ace 7900 front shifter and derailleur and after my shifting cables have been replaced I have noticed the following.

I cannot trim anymore. The chain jumps onto the big chainring with only 1 click. Previously I could shift into the big ring with 2 clicks.

I cannot shift into the small ring. Well I can but the chain stays on the big ring while I pedal. Only after I turn the cranks for a while the chain drops into the small ring.

I can rule out worn cables and housing since those were replaced right as this problem came up.

I have tried adjusting the cable tension with the barrel adjuster but that yielded no results.

Any ideas ?

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  • Did you replace the cables yourself or have it done by someone else?
    – Swifty
    Oct 19, 2018 at 8:18
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    I had done it at a shop, but since they charge 30 bucks for changing my bartape I wont be going back there
    – zython
    Oct 19, 2018 at 8:37
  • I wont be going back there Good decision. A bike shop that can't even set up a front derailleur to shift properly?
    – Andrew Henle
    Oct 19, 2018 at 11:08
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    @zython Nonetheless, you paid them to do some work for you and they haven't done that work properly. You should take your bike back (once) and get them to fix the mess they created.
    – David Richerby
    Oct 19, 2018 at 12:49
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    Just clarifying - the front derailleur moves left far enough to get into the smaller chainring? Might need a minor tweak to the lower limit screw.
    – Criggie ♦
    Oct 20, 2018 at 1:17

2 Answers 2

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Sounds like you have a bit too much cable tension in your new configuration.

Usually cable tension is tuned with the barrel adjuster you mentioned, but if you cannot get the tension low enough with it, you'll need to loosen the bolt that attaches the cable to the derailleur, give the cable just a bit more slack and try again.

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  • yeah there was too much cable tension and the derailleur was positioned too high
    – zython
    Oct 20, 2018 at 13:18
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The Dura Ace FD-7900 front derailleur does not trim.

Service manual: https://si.shimano.com/api/publish/storage/pdf/en/si/5LB0A/SI-5LB0A-002-ENG.pdf

To improve gear shifting performance, the SIS adjustment method for the FD-7900 front derailleur is slightly different from previous derailleurs. In addition, the trimming mechanism has also been abolished in order to improve shifting performance.

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  • Isn't the trim functionality in the shifter, in the form of several different detent/stops ?
    – Criggie ♦
    Dec 8, 2021 at 22:31

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