Advertise on Bikeforums.net



User Tag List

Results 1 to 6 of 6
  1. #1
    Junior Member
    Join Date
    Sep 2008
    Posts
    7
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    anyone running shimano 105 cranks? what size bb for 42mm chainline?

    I'm doing another cheap build for my daily commute. For those of you running Shimano 105's with 130bcd chainring, what BB size are you using get a 42mm chainline? I want to run the ring on the outside if it's possible.

  2. #2
    A little North of Hell
    Join Date
    Mar 2006
    Posts
    4,294
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    octalink

    ring on the inside 41.5 +/- with 109.5 bb
    [SIGPIC][/SIGPIC]
    XXXI

  3. #3
    Senior Member
    Join Date
    Sep 2006
    Location
    Van BC
    Posts
    3,739
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    What Soil Sampler said for octalink---afaik there isn't a shorter one available. If you have some old square taper 105, you can get a 107mm bb and run your ring on the outside at 43~ mm. Slamming the crank in that close can create clearance issues depending on your frame---you'll just have to try it and see. I had to file the horizontal tabs that hold the inner ring back a mm or so on my 600s. But it does work fine now.

  4. #4
    Senior Member filtersweep's Avatar
    Join Date
    Mar 2004
    Posts
    2,615
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You might just try whatever BB you already have, if it is on the cheap. My quietest bike has the worst chainline--- some square taper that just happened to be in stock when I was running it with gears (attached to a Stronglight road crank). Go figure.

  5. #5
    Live without dead time
    Join Date
    Jun 2008
    Location
    Toronto
    Posts
    2,137
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    On my roomates bike I set up a single speed drivetrain using 110mm Shimano Octalink BB and the chainline is just fine. I have never taken the time to measure it, but eyeballing it is close enough. 1 or 2 mm does not matter
    Rich

  6. #6
    Senior Member
    Join Date
    Sep 2006
    Location
    Van BC
    Posts
    3,739
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    ^^ Yes twitcho, Shimano doubles + their recommended bb generally put the inner ring at close-enough-to-42, outer ring at 46ish. The trick for people like op is to find a short enough bb and sufficient clearance to get the outer ring to 42ish.
    Last edited by mander; 11-24-09 at 07:19 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
  •