Advertise on Bikeforums.net



User Tag List

Results 1 to 9 of 9
  1. #1
    Junior Member
    Join Date
    May 2009
    Posts
    11
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Smallest chainring is scratching the frame with a new cartridge bottom bracket.

    Hi,
    i just got my bottom bracket change on my hybrid at a bike shop.
    And when i tried to put back my cranks set, the smallest chainring is so close to the chain stays it is really hard to spin the crank and scratching it.

    I know that before changing the bottom bracket, the crank was fine, and tried a other crank set and same result.

    So can it be the bottom bracket ?
    Can a cartridge bottom bracket been adjust ?
    I'm new to repairing bike, and from what i understood it can't.

  2. #2
    Senior Member
    Join Date
    Feb 2005
    Location
    Oklahoma
    My Bikes
    Trek 5500, Colnago C-50
    Posts
    9,032
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Is the crankset a triple?
    If so is the bottom bracket for a triple?

    Al

  3. #3
    Junior Member
    Join Date
    May 2009
    Posts
    11
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yes it is a triple crankset.

    How could I know if it made for a triple ? (without removing it)

    The mechanic at the bike store, showed me a bottom bracket, told me it is the same thing I had.
    And he told me to come back when it would be done, so I assume he got the right one.

    I guess my mistake was to remove my crankset at home to fit it more easily in the car.
    I should have bring it with me, and that whole thing most likely wouldn't have happen.

  4. #4
    Senior Member johnknappcc's Avatar
    Join Date
    Feb 2009
    Location
    Columbus, OH
    My Bikes
    A beautiful columbus steel frame, 1986 Schwinn Voyageur touring bike, Currently Undergoing Overhaul
    Posts
    910
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Sounds like the BB spindle is too short for your crankset. If you previously had an aymmetrical spindle, the cartridge BB would need to be longer (symmetrically) to compensate for the difference. For example I have a 121.5 asymmetrical spindle for a triple. A similar cartidge BB would need to be 127mm to compensate and still give me the appropriate chainline/clearance. More info would be helpful

  5. #5
    Senior Member Torchy McFlux's Avatar
    Join Date
    Sep 2007
    Location
    Vancouver
    My Bikes
    NOYB
    Posts
    1,397
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The bottom bracket spindle length is wrong for your crank.
    Take it back to the shop (with the crank) and have them install one with a longer spindle for you.

  6. #6
    Junior Member
    Join Date
    May 2009
    Posts
    11
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks all, gonna head back to the bikeshop, as soon as I can to see what they can do.

  7. #7
    Senior Member
    Join Date
    Feb 2005
    Location
    Oklahoma
    My Bikes
    Trek 5500, Colnago C-50
    Posts
    9,032
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Senkarst View Post
    Yes it is a triple crankset.

    How could I know if it made for a triple ? (without removing it)

    The mechanic at the bike store, showed me a bottom bracket, told me it is the same thing I had.
    And he told me to come back when it would be done, so I assume he got the right one.

    I guess my mistake was to remove my crankset at home to fit it more easily in the car.
    I should have bring it with me, and that whole thing most likely wouldn't have happen.
    Did you give the old bottom bracket to the mechanic and ask for the same one?
    Did you tell the mechanic it was for a triple?

    It sounds like the mechanic made the mistake. Learning to do your own wrenching is a good thing. The only thing you may have done wrong was not offering enough information. I think you did the right thing.

  8. #8
    OUTLAW BIKER merckx_rider's Avatar
    Join Date
    Aug 2008
    Location
    So Cal
    My Bikes
    Eddy Merckx team 7-11 Corsa Extra Full Dura Ace
    Posts
    459
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Senkarst View Post
    Hi,
    i just got my bottom bracket change on my hybrid at a bike shop.
    And when i tried to put back my cranks set, the smallest chainring is so close to the chain stays it is really hard to spin the crank and scratching it.

    I know that before changing the bottom bracket, the crank was fine, and tried a other crank set and same result.

    So can it be the bottom bracket ?
    Can a cartridge bottom bracket been adjust ?
    I'm new to repairing bike, and from what i understood it can't.
    Sounds like the shop installed the wrong BB
    http://www.gotbiz.com/uweb/images/freewebsite_uweb.gif The Creator of Uweb! Worlds Best Online Webpage Editor only available at gotbiz.com
    Free Website for your business at gotbiz.com

  9. #9
    Senior Member johnknappcc's Avatar
    Join Date
    Feb 2009
    Location
    Columbus, OH
    My Bikes
    A beautiful columbus steel frame, 1986 Schwinn Voyageur touring bike, Currently Undergoing Overhaul
    Posts
    910
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Oh, one other thing. If it is a square taper, make sure he used the proper taper (either JIS or ISO). But most likely, the spindle length is wrong.

Posting Permissions

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