Bottom bracket knocking

Discussion in 'Cycling Equipment' started by Paul Bobby, Jun 30, 2003.

Thread Status:
Not open for further replies.
  1. Paul Bobby

    Paul Bobby Guest

    Any ideas about what to do about this would be greatly appreciated.

    Have noticed a knocking/popping sound coming from the area of the bottom bracket. Getting worse over
    the last few weeks- can practically feel
    it. Knock occurs with every pedal revolution when the right foot hits 2-3 O'clock. More pronounced
    when spinning at higher rpm.

    Crankarms are tight. Not from the pedals (swapped pedals from another bike). Not chain related
    (persists when spinning in my living room with the chain off the chainring).
     
    Tags:


  2. > Have noticed a knocking/popping sound coming from the area of the bottom bracket. Getting worse
    > over the last few weeks- can practically feel
    > it. Knock occurs with every pedal revolution when the right foot hits 2-3 O'clock. More
    > pronounced when spinning at higher rpm.

    A knocking noise that's repeatable like that shouldn't be too touch to find. For starters, you
    should grab each crank arm with one of your hands, and see if you can rock them back and forth
    (laterally, perpendicular to the direction the chain moves). If you can feel it but not see where
    it's coming from, have someone else help out by placing a finger on the area where the bottom
    bracket spindle comes out of the frame... they should be able to detect what part's moving.

    There really aren't all that many possibilities. If it's definitely coming from your cranks, and
    it's not your pedals, then it's almost got to be either the axle within the bottom bracket (perhaps
    shot bearings), or the bottom bracket assembly is loose on one side or the other (or perhaps both).
    If it's a loose bottom bracket assembly, you need to remove both crank arms, loosen the bottom
    bracket cup on the side opposite the chainrings, fully tighten the chainring side, and then tighten
    the other.

    --Mike-- Chain Reaction Bicycles http://www.ChainReactionBicycles.com

    "Paul Bobby" <[email protected]> wrote in message news:[email protected]...
    > Any ideas about what to do about this would be greatly appreciated.
    >
    > Have noticed a knocking/popping sound coming from the area of the bottom bracket. Getting worse
    > over the last few weeks- can practically feel
    > it. Knock occurs with every pedal revolution when the right foot hits 2-3 O'clock. More
    > pronounced when spinning at higher rpm.
    >
    > Crankarms are tight. Not from the pedals (swapped pedals from another bike). Not chain related
    > (persists when spinning in my living room with the chain off the chainring).
     
  3. "Paul Bobby" <[email protected]> wrote in message news:[email protected]...
    > Any ideas about what to do about this would be greatly appreciated.
    >
    > Have noticed a knocking/popping sound coming from the area of the bottom bracket. Getting worse
    > over the last few weeks- can practically feel
    > it. Knock occurs with every pedal revolution when the right foot hits 2-3 O'clock. More
    > pronounced when spinning at higher rpm.
    >
    > Crankarms are tight. Not from the pedals (swapped pedals from another bike). Not chain related
    > (persists when spinning in my living room with the chain off the chainring).

    Same problem happened to my bike. I took out the bottom bracket wrapped the threads in plumbers
    Teflon tape and reinstalled. No knocking, clicking or popping

    -N
     
Loading...
Thread Status:
Not open for further replies.
Loading...