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Bottom Bracket?

Started by Noel · · Last activity · 12 posts · 493 views

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Original section
UK and Europe
Published
31 January 2007
Last activity
1 February 2007
Original author
Noel
Posts
12
Discussion status
Public discussion
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493
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  1. Hi,

    I was out yesterday and noticed a slight loose movement in the cranks.
    When I got home I examined the bike and there is some distinct movement
    when I push/pull the cranks sideways.

    Would I be right in thinking this is the bottom bracket that needs fixing?

    I am a little reticent about taking it to the LBS immediately as I ended
    up having a new bottom bracket fitted to my old bike when it later
    transpired the clicking noise during rotation was nothing more than some
    grit in the pedals. Definitely not grit this time but it would be nice to
    go armed with some probable causes.

    Cheers
    Noel

  2. Noel said:

    Hi,

    I was out yesterday and noticed a slight loose movement in the cranks.
    When I got home I examined the bike and there is some distinct movement
    when I push/pull the cranks sideways.

    Would I be right in thinking this is the bottom bracket that needs fixing?

    I am a little reticent about taking it to the LBS immediately as I ended
    up having a new bottom bracket fitted to my old bike when it later
    transpired the clicking noise during rotation was nothing more than some
    grit in the pedals. Definitely not grit this time but it would be nice to
    go armed with some probable causes.

    If you have the tools, it might be worth seeing if it has worked loose
    and just needs to be tightened up.

    --
    Don Whybrow

    Sequi Bonum Non Time

    People must not do things for fun. We are not here for fun.
    There is no reference to fun in any Act of Parliament.

  3. On 31/01/2007 20:17, Noel said,

    Quoted message said:

    Would I be right in thinking this is the bottom bracket that needs fixing?

    What is it with bottom brackets at the moment? Have they come into
    season???

    Is it the whole crankset moving sideways, or just one arm? If the
    former, then it sounds like the bottom bracket at the very least needs
    adjusting. Make sure the right hand cup is tight (tightens
    anti-clockwise), then adjust the left hand cup (tightens clockwise)
    until the play has gone. If the play disappears but you end up with a
    stiff or graunchy bottom bracket, the technical term for this condition
    is "knackered".

    Quoted message said:

    I am a little reticent about taking it to the LBS immediately as I ended
    up having a new bottom bracket fitted to my old bike when it later
    transpired the clicking noise during rotation was nothing more than some
    grit in the pedals.

    Sounds like you might need to change your LBS :-)

    --
    Paul Boyd
    http://www.paul-boyd.co.uk/

  4. Noel said:

    Hi,

    I was out yesterday and noticed a slight loose movement in the cranks.
    When I got home I examined the bike and there is some distinct
    movement when I push/pull the cranks sideways.

    Would I be right in thinking this is the bottom bracket that needs
    fixing?

    Most likely the bottom bracket's bearings are knackered if it's the same
    with both cranks. A modern BB can't be fixed; the whole thing has to be
    replaced.

    ~PB

  5. Pete Biggs said:

    Most likely the bottom bracket's bearings are knackered if it's the same
    with both cranks. A modern BB can't be fixed; the whole thing has to be
    replaced.

    Just replaced the outboard bearings on an Ultegra. Ofcourse their was
    already a nasty groove worn in the non-replacable axle. Silly design

    --
    ---
    Marten Gerritsen

    INFOapestaartjeM-GINEERINGpuntNL
    www.m-gineering.nl

  6. M-gineering said:
    Pete Biggs said:

    Most likely the bottom bracket's bearings are knackered if it's the
    same with both cranks. A modern BB can't be fixed; the whole thing
    has to be replaced.

    Just replaced the outboard bearings on an Ultegra. Ofcourse their was
    already a nasty groove worn in the non-replacable axle. Silly design

    I don't call these outboard things "bottom brackets" ;-)

    ~PB

  7. Pete Biggs said:
    M-gineering said:
    Pete Biggs said:

    Most likely the bottom bracket's bearings are knackered if it's the
    same with both cranks. A modern BB can't be fixed; the whole thing
    has to be replaced.


    Just replaced the outboard bearings on an Ultegra. Ofcourse their was
    already a nasty groove worn in the non-replacable axle. Silly design

    I don't call these outboard things "bottom brackets" ;-)

    ~PB


    Agreed, Shimano should give them a BR part number 😉

    --
    ---
    Marten Gerritsen

    INFOapestaartjeM-GINEERINGpuntNL
    www.m-gineering.nl

  8. Paul Boyd said:

    Is it the whole crankset moving sideways, or just one arm? If the

    Yes both.

    Quoted message said:

    Sounds like you might need to change your LBS :-)

    Yes done that too! Took to LBS2 today and sure enough the BB is
    knackered. LBS2 then called up later to say it was also seized into the
    frame as well which is a little worrying as this Claude Butler is only a
    year old.

    Cheers
    Noel

  9. In article
    <[email hidden]>, Noel

    Quoted message said:
    Quoted message said:

    Is it the whole crankset moving sideways, or just one arm? If
    the

    Quoted message said:

    Yes both.

    Quoted message said:

    Sounds like you might need to change your LBS :-)

    Quoted message said:

    Yes done that too! Took to LBS2 today and sure enough the BB is
    knackered. LBS2 then called up later to say it was also seized
    into the frame as well which is a little worrying as this Claude
    Butler is only a year old.

    Time for LBS3 methinks.

    --
    T h e - e x t e n d e r ! ! ! !

  10. M-gineering said:
    Pete Biggs said:

    Most likely the bottom bracket's bearings are knackered if it's the same
    with both cranks. A modern BB can't be fixed; the whole thing has to be
    replaced.

    Just replaced the outboard bearings on an Ultegra. Ofcourse their was
    already a nasty groove worn in the non-replacable axle. Silly design

    OK, that sounds a bit worrying. What caused that? Seized bearing?

    --
    Mike
    Van Tuyl titanium Dura Ace 10
    Fausto Coppi aluminium Ultegra 10
    Raleigh Record Sprint mongrel

  11. mb said:
    M-gineering said:
    Pete Biggs said:

    Most likely the bottom bracket's bearings are knackered if it's the same
    with both cranks. A modern BB can't be fixed; the whole thing has to be
    replaced.


    Just replaced the outboard bearings on an Ultegra. Ofcourse their was
    already a nasty groove worn in the non-replacable axle. Silly design

    OK, that sounds a bit worrying. What caused that? Seized bearing?

    It starts with ignoring everything taught about bearing design. With a
    rotating load as in a crankset you want a pressfit on the axle (to
    prevent the axle from wandering in the bearing ring) and a loose fit (to
    prevent the bearings seizing) on the outer ring of the bearing. A this
    is a bicycle *) it is built the other way round. Which means that there
    will be a lot of movement on the axle-bearing interface, even with the
    bearing in good nick. It probably doesn't need much rust in the bearing
    for the movement to increase appreciably. <shudder>And this was an
    Ultegra, 105 has an aluminium axle! </shudder>

    *) as per another chapter of the universal bicycle design guide
    --
    ---
    Marten Gerritsen

    INFOapestaartjeM-GINEERINGpuntNL
    www.m-gineering.nl

  12. M-gineering said:
    mb said:
    M-gineering said:

    Just replaced the outboard bearings on an Ultegra. Ofcourse their was
    already a nasty groove worn in the non-replacable axle. Silly design

    OK, that sounds a bit worrying. What caused that? Seized bearing?

    It starts with ignoring everything taught about bearing design. With a
    rotating load as in a crankset you want a pressfit on the axle (to
    prevent the axle from wandering in the bearing ring) and a loose fit (to
    prevent the bearings seizing) on the outer ring of the bearing. A this
    is a bicycle *) it is built the other way round. Which means that there
    will be a lot of movement on the axle-bearing interface, even with the
    bearing in good nick. It probably doesn't need much rust in the bearing
    for the movement to increase appreciably. <shudder>And this was an
    Ultegra, 105 has an aluminium axle! </shudder>

    *) as per another chapter of the universal bicycle design guide

    Thanks, I'll have to keep an eye on mine. Nothing like that happening yet.

    --
    Mike
    Van Tuyl titanium Dura Ace 10
    Fausto Coppi aluminium Ultegra 10
    Raleigh Record Sprint mongrel

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