Advertise on Bikeforums.net



User Tag List

Results 1 to 7 of 7
  1. #1
    Fearless Isaiahc72's Avatar
    Join Date
    Sep 2013
    Location
    Northwest Arkansas
    My Bikes
    2014 Trek 7.1 FX, '95 Giant Attraction
    Posts
    247
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)

    Chain going off large chainring?

    I had my chain go off my largest front chainring the other night but was able to down shift and get it back on before it got out of control. However I haven't adjusted my limit screw since and also haven't had any issues like that. So I'm wondering, is it normal for this to happen every once-in-a-while? Or should I really try and restrict my limit screw adjustment to be closer to the chain?
    IC

  2. #2
    johnliu@earthlink.net jyl's Avatar
    Join Date
    Aug 2006
    Location
    Portland OR
    My Bikes
    61 Bianchi Specialissima 71 Peugeot G50 7? P'geot PX10 74 Raleigh GranSport 75 P'geot UO8 78? Raleigh Team Pro 82 P'geot PSV 86 P'geot PX 91 Bridgestone MB0 92 B'stone XO1 97 Rans VRex 92 Cannondale R1000 94 B'stone MB5 97 Vitus 997
    Posts
    4,029
    Mentioned
    53 Post(s)
    Tagged
    0 Thread(s)
    It isn't normal for the chain to overshift off the large chainring, if that is what happened. I would check front derailleur adjustment. Park Tools website or Sheldon Brown website have procedures for this.
    Your signature contains too many lines and must be shortened. You may only have up to 2 line(s). Long text may have been implicitly wrapped, causing it to be

  3. #3
    Senior Member eja_ bottecchia's Avatar
    Join Date
    Jul 2010
    Posts
    3,406
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jyl View Post
    it isn't normal for the chain to overshift off the large chainring, if that is what happened. I would check front derailleur adjustment. Park tools website or sheldon brown website have procedures for this.
    ^^^this^^^
    My current stable:

    1989 SLX Bottecchia (Campy Athena 11s)
    1999 Cannondale F400 mountain bike
    2012 Bianchi Infinito (Campy Record 11s)
    2012 Colnago C59 in PR99 color scheme (Campy Record 11s)

  4. #4
    Senior Member Duane Behrens's Avatar
    Join Date
    Mar 2010
    Location
    Minnesota and Southern California
    My Bikes
    2009 Specialized Tarmac (CF), 1980 Nishiki (steel), 1984 Raleigh Super Course (steel), 1988 Schwinn World Sport (steel), 2009 Sp. Roubaix (carbon)
    Posts
    574
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    With the bike on the stand, use your left shifter (FD) and try to move the chain off the right side of the large ring. If you can, it needs adjustment. With most FDs, the adjustment is an eighth to a quarter turn clockwise on the screw closest to the rings. Check chain wear first. Best.
    The biggest fools are those who cannot suffer fools gladly. -Perzuki

  5. #5
    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
    25,820
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    Tiny adjustments to the limit screws (1/8 turn or so at a time ) should fix the problem. Agree, it's not normal or acceptable.

  6. #6
    Recreational Commuter
    Join Date
    Apr 2006
    Location
    Central Ohio
    My Bikes
    Two brand-less build-ups.
    Posts
    998
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It can be a little bit more complicated if you have indexed shifting.

    If the front derailleur is a "high normal" type (the derailleur heads toward the big ring when the cable is slack, these are less common) then you adjust the high limit screw first so that you can just get cleanly onto the big ring, then the cable tension so that the shifts to the smaller rings work smoothly.

    If the front derailleur is "low normal" (the derailleur heads towards the small ring when the cable is slack, most common) then you adjust the cable tension first so that you can just get cleanly onto the big ring, then the high limit screw, leaving a slight bit of room for overshifting. If you get the high limit screw too tight, it can interfere with shifting because the derailleur may need to move a tiny bit outward past the ideal position before moving inward (depending on the design of your shifters, some pull on the cable a bit extra to clear pawls internally, then let it settle back.)

    Either way, you may need to go a few passes between cable tension and limit screws.

    Of course, none of the above applies with friction shifting. Set your limit screws so you don't dump the chain off, and go ride.
    Riding the Ohio MS Central Ohio Challenge tour, July 12th.

  7. #7
    Senior Member Homebrew01's Avatar
    Join Date
    Jul 2004
    Location
    Ffld Cnty Connecticut
    My Bikes
    Old Steelies I made, Old Cannondales
    Posts
    15,839
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    If you are in one of the smaller cogs in back, it might be a bit more likely to overshift off the front ring because the chains is already outboard. Whereas if you are on a larger cog in back the chain is inboard and slightly more resistant to being overshifted. When adjusting the front, I usually check that it works both directions in combination with different gears in back.
    Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike

Posting Permissions

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