7800 fd woes...- Mtbr.com
Results 1 to 5 of 5

Thread: 7800 fd woes...

  1. #1
    mtbr member
    Reputation:
    Join Date
    Apr 2007
    Posts
    322

    7800 fd woes...

    I picked up a nice 7800 front derailleur but I cant seem to get it to work for my double.
    Running 9 speed rear, 22/32 front. Always seems to be some cross over rubbing.
    If this will not work with any combination its not worth it, ill go back to an x0 which I know worked. I am using bottom pull, no adapter needed.
    Heres listing:
    Shimano Dura-Ace 7800 Front Derailluer -- 34.9 Clamp - eBay (item 130556774243 end time Aug-11-11 19:30:43 PDT)

    Is this meant for 10 speed...?
    What am I missing...?

    More info: I am using X9 triggers. Probably switch back to my grip shifters, which will help with the trim.
    I remember seeing pictures of the cage measurement for the 7800 and 7900. I can't remember which had the larger cage though.
    Last edited by OuterNational; 08-18-2011 at 07:26 AM.

  2. #2
    mtbr member
    Reputation: limba's Avatar
    Join Date
    Jan 2004
    Posts
    2,938
    The 7900 is wider.

    http://forums.mtbr.com/weight-weenie...6g-618252.html

    You might want to try a thinner 10 speed chain too. A 10 speed chain will work on a 9 speed cassette.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Apr 2007
    Posts
    322
    anyone want to trade my 7800 for your 7900?

  4. #4
    Always Learning
    Reputation: BruceBrown's Avatar
    Join Date
    Jan 2004
    Posts
    9,606
    Quote Originally Posted by OuterNational View Post
    I picked up a nice 7800 front derailleur but I cant seem to get it to work for my double.
    Running 9 speed rear, 22/32 front. Always seems to be some cross over rubbing.
    If this will not work with any combination its not worth it, ill go back to an x0 which I know worked. I am using bottom pull, no adapter needed.
    Heres listing:
    Shimano Dura-Ace 7800 Front Derailluer -- 34.9 Clamp - eBay (item 130556774243 end time Aug-11-11 19:30:43 PDT)

    Is this meant for 10 speed...?
    What am I missing...?

    More info: I am using X9 triggers. Probably switch back to my grip shifters, which will help with the trim.
    I remember seeing pictures of the cage measurement for the 7800 and 7900. I can't remember which had the larger cage though.
    I use one on my Dos Niner with a 2 x 9 set up. And I have a 7900 on my JET 9 with a 2 x 9 drivetrain. Both with 9 speed chains. In both cases, I had to modify the cable pull by doing some grinding so it would pull out more distance of the big ring on my bikes. I think Nino had a thread on that mod here on the forum way back when I did the mod on the 7800. I don't have a link, but I'm sure a search would turn it up.

    Obviously, the 7900 is wider and I have less issues with it, but I've got my 7800 tuned and lined up so I can use all gears. There is some slight rubbing on the extreme chain crossing of gears, but I don't use those combinations very often.

    That being said, if I was buying again for another 2 x 9 - I would give a for the 7900.

    BB

  5. #5
    Hack Racer
    Reputation: Cheers!'s Avatar
    Join Date
    Jun 2006
    Posts
    2,559
    I ran the 7800 on my middleburn DUO 2x9 w/ 29/40 chainring combo. The 7800 required ridiculous amounts of force by the left shifter to shift it. It also had troubles swinging the cage far enough for the big chainring. In the end I said forget it and got a XTR M970 front derailleur. It worked well. But again the derailleur wouldn't shift from small to big correctly. It also suffered having enough range to swing the cage far enough out.

    I have since ditched the left side M970 shifter. Got a M980 shifter. Then got the M985 front derailleur for double setups. I use this on my middleburn duo. Shifts as smooth as butter.

Similar Threads

  1. Jet9 - SLX Crank mod to 2x9 with DA 7800?
    By db9 in forum Niner Bikes
    Replies: 0
    Last Post: 07-14-2011, 05:39 AM
  2. Tallboy with DA FD-7800 anyone?
    By Dikkie in forum Santa Cruz
    Replies: 0
    Last Post: 12-02-2010, 01:09 PM
  3. Dura Ace RD-7700 and RD-7800
    By TunicaTrails in forum Weight Weenies
    Replies: 34
    Last Post: 08-31-2010, 08:06 AM
  4. XTR 960 Crank with a 7800 Dura Ace BB?
    By mf9point8 in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 4
    Last Post: 10-09-2008, 09:07 AM
  5. DA 7800 BB + XTR M960 crankarms?
    By Buoyen in forum Weight Weenies
    Replies: 0
    Last Post: 02-24-2007, 03:12 PM

Members who have read this thread: 0

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.