Viewing 12 posts - 1 through 12 (of 12 total)
  • Tell me about 3-piece bottom brackets
  • foxyrider
    Free Member

    My mate has an old Mercian Road bike (1980’s I think) in which the BB is totally worn. I have looked up and using a pipe wrench & spanner (I haven’t got a BB hook spanner) I reckon I should be able to remove the lock ring and cups – depending on what it looks like inside do you think I am best measuring the BB shell and axle length and replacing the whole lot?

    foxyrider
    Free Member

    Anyone?

    wwaswas
    Full Member

    if the bearing surfaces are at all worn then yes, you could clean it all up, replace the bearings and regrease but it won’t take long for it to get bad again.

    it’s the sort of job that an ‘old fashioned’ LBS will be able to do in half the time, have the right tools to do and probably have the necessary parts in stock too, though…

    foxyrider
    Free Member

    He wants to pay me for doing it so wouldn’t be charity – I just thought I could poss replace the BB with a campag cartridge of the same size I would have thought?

    Macavity
    Free Member

    “replace the BB with a campag cartridge “

    is it a Campagnolo chainset?
    is it a square taper type?
    If it is a square taper Campagnolo chainset then replace with a Campagnolo square taper BB ?
    The taper on Campagnolo Square taper (although 4 degrees, same as Shimano etc) is narrower than other makes based on the JIS standard.
    So a Campagnolo chainset would not slide far enough onto a Shimano (JIS) BB axle.

    But old cranks are not famous for reliability
    http://pardo.net/bike/pic/fail-001/FAIL-039.html

    foxyrider
    Free Member

    I think its might be campag compatible but he replaced it with another crank in the 80’s – not sure which make yet. I have an old campag BB so I can compare. It is square taper 3 part BB like this:

    Looks adjustable – Maybe it is JIS std like you say – I need to take it apart to make sure as I have only had a quick look so far 🙁

    Found this on Sheldons site:

    http://www.sheldonbrown.com/tooltips/bbcups.html

    thanks Mac 🙂

    rootes1
    Full Member

    how do you know it is worn if you have not taken it apart? could just be our of adjustment.. i.e. the adjustable cup has come loose

    might get away with a clean, a new set of balls, grease and proper ajustment

    foxyrider
    Free Member

    how do you know it is worn if you have not taken it apart? could just be our of adjustment.. i.e. the adjustable cup has come loose

    I did have that very same thought as I wrote the above 🙂

    Tiz boody old BB though 🙂

    Cheers for the comments 🙂 Got it a bit more sorted plan wise 🙂

    cynic-al
    Free Member

    If it’s in good nick then re-grease, otherwise UN54 – while campag/shim cranks sit a bit in/out (can’t remember which way) it can still work.

    Oh and not all old cranks break!

    Be careful removing the lockring as they are easily damaged.

    cynic-al
    Free Member

    If it’s in good nick then re-grease, otherwise UN54 – while campag/shim cranks sit a bit in/out (can’t remember which way) it can still work.

    Oh and not all old cranks break!

    Be careful removing the lockring as they are easily damaged.

    foxyrider
    Free Member

    Cheers cynic-al – yeh I’ll try not to mash his ring 😡 The cranks look in very good nick really 🙂 ATM he is using it on his turbo but with the aim I think to resurrect it as and when he can replace bits 🙂

    Macavity
    Free Member

    They do not always break
    http://pardo.net/bike/pic/fail-001/FAIL-001.html
    and Shimano BB axles (JIS standard) are fatter to try to avoid breakages.

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