Advertise on Bikeforums.net



User Tag List

Results 1 to 11 of 11
  1. #1
    Senior Member
    Join Date
    Apr 2010
    Location
    Fredericton, NB, Canada
    My Bikes
    2010 S1, 2011 F75X
    Posts
    1,424
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Raising front derailleur height - am I overthinking it?

    Cervelo S1 with 6600 Ultegra braze on FR, compact 50T outer chainring.

    I now have a 50T Rotor Q ring sitting in my basement ready to go on. I can only assume I'll need to raise the FR slightly to clear the oval ring.

    Is it as simple as loosening the braze on, raising the FR a bit, and tighten? I'm also assuming I'll have to loosen off the FR cable as I raise it to maintain proper tension. Tighten, then fine tune with barrel adjuster?

  2. #2
    coprolite fietsbob's Avatar
    Join Date
    Jun 2010
    Location
    NW,Oregon Coast
    My Bikes
    7
    Posts
    3,182
    Mentioned
    46 Post(s)
    Tagged
    0 Thread(s)
    ... So no mechanical aptitude? software writer?

    The bolt that goes thru the derailleur.. that one..

    Think about a K Edge chain catcher, to also bolt on, with that bolt,
    perhaps a longer bolt. chain suck destroys carbon frames,
    so best be prevented..

    http://www.acecosportgroup.com/shop/
    Last edited by fietsbob; 04-16-11 at 01:24 PM.

  3. #3
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    26,143
    Mentioned
    13 Post(s)
    Tagged
    0 Thread(s)
    Yep, that's pretty much it. Disconnect the fd's cable, loosen the clamp bolt and reposition the derailleur so the cage misses the closest chainring teeth by ~2 mm, check alignment and tighten the bolt. Then reconnect the cable and adjust the tension to get the shifting right.

  4. #4
    Mad bike riding scientist cyccommute's Avatar
    Join Date
    Nov 2004
    Location
    Denver, CO
    My Bikes
    Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
    Posts
    15,966
    Mentioned
    24 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by HillRider View Post
    Yep, that's pretty much it. Disconnect the fd's cable, loosen the clamp bolt and reposition the derailleur so the cage misses the closest chainring teeth by ~2 mm, check alignment and tighten the bolt. Then reconnect the cable and adjust the tension to get the shifting right.
    A nickel makes a very nice feeler gauge for the cage/chainring gap.
    Stuart Black
    Solo Without Pie. The search for pie in the Midwest.
    Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
    Days of Wineless Roads. Bed and Breakfasting along the KATY
    Twisting Down the Alley. Misadventures in tornado alley.
    An Good Ol' Fashion Appalachian Butt Whoopin'.

  5. #5
    Senior Member digibud's Avatar
    Join Date
    Oct 2009
    Location
    Further North than U
    My Bikes
    Spec Roubaix, three Fisher Montare, two Pugs
    Posts
    1,542
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    but the thing to watch carefully is the angle of the derailler. Even a very small toe-in or toe-out can change shifting characteristics. Getting the vertical height is easy, getting the angle very nicely perfect can be tricky so take care with that.

  6. #6
    Mad bike riding scientist cyccommute's Avatar
    Join Date
    Nov 2004
    Location
    Denver, CO
    My Bikes
    Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
    Posts
    15,966
    Mentioned
    24 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by digibud View Post
    but the thing to watch carefully is the angle of the derailler. Even a very small toe-in or toe-out can change shifting characteristics. Getting the vertical height is easy, getting the angle very nicely perfect can be tricky so take care with that.
    With a braze-on derailer, alignment of the derailer is much easier and less likely to be too far out of optimal. You can adjust the angle but not nearly as much as you can with a clamp.
    Stuart Black
    Solo Without Pie. The search for pie in the Midwest.
    Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
    Days of Wineless Roads. Bed and Breakfasting along the KATY
    Twisting Down the Alley. Misadventures in tornado alley.
    An Good Ol' Fashion Appalachian Butt Whoopin'.

  7. #7
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    26,143
    Mentioned
    13 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by cyccommute View Post
    With a braze-on derailer, alignment of the derailer is much easier and less likely to be too far out of optimal. You can adjust the angle but not nearly as much as you can with a clamp.
    That's why I like braze-on front derailleurs used with an adapter clamp. I can remove just the derailleur for cleaning and not disturb the height or alignment setting by not removing the adapter.

  8. #8
    in cog neato itsmoot's Avatar
    Join Date
    Mar 2008
    Location
    Missouri
    Posts
    354
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fietsbob View Post
    ... So no mechanical aptitude? software writer?

    The bolt that goes thru the derailleur.. that one..

    Think about a K Edge chain catcher, to also bolt on, with that bolt,
    perhaps a longer bolt. chain suck destroys carbon frames,
    so best be prevented..

    http://www.acecosportgroup.com/shop/
    Your link doesn't work, looks like you need to put a space between the link and the "innocent" smiley you used.

    - a software writer with mechanical aptitude

    I have the heart of a young boy. I got it on eBay.

  9. #9
    Senior Member
    Join Date
    Apr 2010
    Location
    Fredericton, NB, Canada
    My Bikes
    2010 S1, 2011 F75X
    Posts
    1,424
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks for the help guys.

    Very easy process. Had to tweak the cable tension and toe in/out after raising the FR. So far, loving the Q ring.

  10. #10
    Fax Transport Specialist black_box's Avatar
    Join Date
    May 2008
    Location
    chicago burbs
    My Bikes
    '07 fuji cross pro, '10 gary fisher x-caliber
    Posts
    850
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    if the FD is too low, would that cause binding when shifting into the large chainring? I'm trying to fix my girlfriend's Sora triple FD which does this. The chain seems to get pinched between the FD and the outer chainring when shifting up to it. I've only eyeballed it so far, but both of my bikes seem to have a higher position. The front, inside edge of the cage has a bulge towards the chainring, I think this is what's hitting the chain. Or could it just be the high limit stop is too far outside?

  11. #11
    cab horn
    Join Date
    Jun 2004
    Location
    Toronto
    My Bikes
    1987 Bianchi Campione
    Posts
    28,295
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by black_box View Post
    if the FD is too low, would that cause binding when shifting into the large chainring? I'm trying to fix my girlfriend's Sora triple FD which does this. The chain seems to get pinched between the FD and the outer chainring when shifting up to it. I've only eyeballed it so far, but both of my bikes seem to have a higher position. The front, inside edge of the cage has a bulge towards the chainring, I think this is what's hitting the chain. Or could it just be the high limit stop is too far outside?
    If you're doing this test on the stand you might just not be 'pedalling' hard enough.

    If it's jamming, check that the inner plate isn't hitting the middle ring. That would be caused by having the derailleur too low, even if it clears the large ring.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

Posting Permissions

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