Results 1 to 8 of 8
  1. #1
    mtbr member
    Reputation: breckenridge's Avatar
    Join Date
    Jul 2012
    Posts
    216

    3x9 front derailleur cage tire clearance

    The tire clearance to the cage on my old X7 3x9 front derailleur was pretty close on my Jamis Dragon Sport when in the granny ring. I just upgraded to a x9, and the slightly wider cage is even closer, maybe only a millimeter or two of clearance. The crank and BB are original. Has anyone successfully modified a cage for more clearance? I'd like to stay 3x9 if possible, but would consider 2x9. Different crank and bottom bracket? Any ideas?

    Thanks!
    Attached Thumbnails Attached Thumbnails 3x9 front derailleur cage tire clearance-2013-01-10_21-31-20_341.jpg  


  2. #2
    mtbr member
    Reputation: breckenridge's Avatar
    Join Date
    Jul 2012
    Posts
    216
    Well, I slept on it and decided to make the jump. Ordered a FSA Afterburner 386 2x9 crankset. The original Sram S800 crank could have used an upgrade anyway.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Feb 2006
    Posts
    1,393
    Have you tried repositioning the derailleur? Angle the nose in a tad, shifting going down will improve.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Jun 2007
    Posts
    510
    You have two options. Changing the crank was not needed though. You just needed to add a spacer or two to your drive side BB and then adjust your low limit screw out. Or get a compact FD.
    High Ho Sultan, Lets GO

  5. #5
    IllumaDucati
    Reputation: Roadsters's Avatar
    Join Date
    Jul 2008
    Posts
    518
    Well, often there are two sides to every story.

    On some bikes, installing a 2.4" tire with big knobbies on the back allows you to use the front derailleur as a handy parking brake.

  6. #6
    mtbr member
    Reputation: breckenridge's Avatar
    Join Date
    Jul 2012
    Posts
    216
    Unfortunately the current bottom bracket is a cheaper Sram one that has internal bearings and isn't adjustable side-side with spacers like an external one. It was a good reason to ditch the low end crank/BB that's on there now anyway.

  7. #7
    ballbuster
    Reputation: pimpbot's Avatar
    Join Date
    Dec 2003
    Posts
    12,628
    Quote Originally Posted by breckenridge View Post
    The tire clearance to the cage on my old X7 3x9 front derailleur was pretty close on my Jamis Dragon Sport when in the granny ring. I just upgraded to a x9, and the slightly wider cage is even closer, maybe only a millimeter or two of clearance. The crank and BB are original. Has anyone successfully modified a cage for more clearance? I'd like to stay 3x9 if possible, but would consider 2x9. Different crank and bottom bracket? Any ideas?

    Thanks!
    Narrower tire?

    I dunno.... do you really need more tire clearance? Move the derailleur up or down on the seat tube... just a tad.

    Quote Originally Posted by breckenridge View Post
    Unfortunately the current bottom bracket is a cheaper Sram one that has internal bearings and isn't adjustable side-side with spacers like an external one. It was a good reason to ditch the low end crank/BB that's on there now anyway.
    ... or replace it with a wider BB.

    Are you sure your crank arms haven't been torqued down too tightly? Square taper BBs are known for being very sensitive to how tight the bolts are. If you over-torque them, the arms are drawn too far in, creating weird chainline or clearance issues.
    Last edited by pimpbot; 01-13-2013 at 08:15 PM.

  8. #8
    mtbr member
    Reputation: breckenridge's Avatar
    Join Date
    Jul 2012
    Posts
    216
    The original BB/crank was a splined spindle, so no issues with over torque/squeezed in arms there. I got the FSA Afterburner dedicated 2x9 crank in yesterday, a much nicer unit than the old SRAM S800, probably lost a half pound anyway. And the tire clearance is now a non-issue. The derailleur cage is in-line with the chainstay bulge for tire clearance, and no farting around with 2x10 part compatibility with 9sp. The 3x9 X9 FD and 3x9 X0 shifters work perfectly in the top two positions. 1-2 had too much pull and was swinging farther than the two chainrings alignments. I am a happy camper.





    Just a little lost on either end, but overall good ratio coverage vs. the old 3x front:
    Last edited by breckenridge; 01-20-2013 at 11:48 AM.

Posting Permissions

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