Advertise on Bikeforums.net



User Tag List

Results 1 to 6 of 6

Thread: Chain Line

  1. #1
    Senior Member afilado's Avatar
    Join Date
    Jul 2007
    Location
    Chattanooga
    My Bikes
    '93 Bridgestone RB-1, '91 Specialized Allez Epic, '85 Raleigh Team Pro, '78 Andre Bertin, early '90s F. Moser Leader AX , '85 Centurion Equipe, '98 Litespeed Tuscany, '89 Klein Quantum, '80 Nishiki Superbe, '83 Peckham, '84 Fuji Opus III
    Posts
    1,172
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)

    Chain Line

    Within 3-5 mm how important is chain line on a multispeed drivetrain?

    I'm building up a hotrod 12 speed from a handbuilt 531 American frame using some favorite but unmatched components. I'm using some odd Italian, Japanese, American and French parts which don't ordinarily go together. Now, I'm almost finished and have to decide on the "correct" BB for a lovely Topline double crankset.

    The Topline is ISO taper (I presume) and fits differently on every BB I've tried - Campy, Shimano, Hatta, Sugino, Suntour, Edco. There's as much as 3+ mm difference in depth of fit because of square taper differences.

    Also, there are various axle lengths to consider, from 112 to 116 mm.

    I think that if I have sufficient clearence from chainstay AND have sufficient depth of fit on square taper that the variance in chainline can be compensated for in available derailleur adjustments.

    Sheldon says that in spite of the JIS/ISO/? differences he's never had a problem compensating. I tend to agree (in theory).

    Comments?

  2. #2
    Seņor Member USAZorro's Avatar
    Join Date
    Oct 2004
    Location
    Carlisle, PA
    My Bikes
    1954 Hetchins M.O., 1959 Viking Severn Valley, 1970 Raleigh Pro, 1972 Fuji "The Finest", 1974 Raleigh Superbe&Comp, 1976 Raleigh Team Pro, 1994 Trek 830 MTB, 2000 Bob Jackson Arrowhead, Unicycle
    Posts
    13,034
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The center of the two rings in the front should be quite close to the center of the freewheel or cassette.
    The search for inner peace continues...

  3. #3
    Senior Member afilado's Avatar
    Join Date
    Jul 2007
    Location
    Chattanooga
    My Bikes
    '93 Bridgestone RB-1, '91 Specialized Allez Epic, '85 Raleigh Team Pro, '78 Andre Bertin, early '90s F. Moser Leader AX , '85 Centurion Equipe, '98 Litespeed Tuscany, '89 Klein Quantum, '80 Nishiki Superbe, '83 Peckham, '84 Fuji Opus III
    Posts
    1,172
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by USAZorro View Post
    The center of the two rings in the front should be quite close to the center of the freewheel or cassette.
    "quite close" is the key phrase. What does that mean? How many mm? I think you confirm my thoughts that it is variable, and there are no hard rules.

  4. #4
    Senior Member Iowegian's Avatar
    Join Date
    Dec 2005
    Location
    Boulder, Colo
    Posts
    1,734
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If it's just a 12 speed and you're using friction shifting, close should be good enough. You might need to trim your FD a bit more than usual if the chainline is off and you'll want to limit the cross chaining but everything should work.

  5. #5
    juneeaa memba!
    Join Date
    Oct 2003
    Location
    boogled up in...Idaho!
    My Bikes
    Crap. The box is not big enough...
    Posts
    5,611
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    eyeballishly close. you don't have to build a jig to measure it.

  6. #6
    Nut infinityeye's Avatar
    Join Date
    Apr 2005
    Location
    Tallahassle, FL
    Posts
    697
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If your front derailleur will throw it, call it good.

    chain line schmain line on old friction rides.

Posting Permissions

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