How many miles out of a bottom bracket?

heavymental
heavymental Posts: 2,076
edited June 2009 in Workshop
I built my bike about 18 months ago using a Campag Chorus BB that I bought second hand. I think the guy told me it had about 500 miles on it and it looked tidy so I've no reason to not believe that. However, I've now put another maybe 2000 miles on it (I don't do alot of miles on this bike) and its started clicking and there is play in the bearings. I was kind of hoping for more out of it to be honest! How many miles would you expect a nearly top end BB to last?

Comments

  • passout
    passout Posts: 4,425
    I got 20 miles out a new Shimano Deore MTB BB once. I had the same before and it lasted years - hard to say.
    'Happiness serves hardly any other purpose than to make unhappiness possible' Marcel Proust.
  • don key
    don key Posts: 494
    I got a second hand chorus 13 months ago and it gave out mid race last week, the chain came off twice as I changed gear on the bend. They are quite long lasting, this one took a fair old beating, a million revs, 5 million , I dont know, good bike shop will though.
  • galaxyboy
    galaxyboy Posts: 168
    Mine has about 5000 miles on it so far. I've just ordered a new rear cassette (1st replacement) and new chain (2nd) and I was thinking of ordering a new BB but as it is not playing up yet I did not order one. Should I replace it anyway?
  • Crapaud
    Crapaud Posts: 2,483
    The BB on my Thorn's done around 10 000 miles and is still solid, no play whatsoever.

    I would expect to get a lot more than 2 500 miles out of a mid-range BB never mind a high end one.

    A quick google informs me that it's a 'how long is a piece of string' question. There doesn't seem to be a definitve - or ever a rough guide - answer to bracket wear.
    A fanatic is one who can’t change his mind and won’t change the subject - Churchill
  • Bhima
    Bhima Posts: 2,145
    It depends on how much pressure you put on it by standing on the pedals climbing, constantly going out-of-the-saddle for sprinting or accellerating from zero on too big a gear. The same things can affect the stress on a chain too.

    Mine's done just over 5000 miles since December.
  • ademort
    ademort Posts: 1,924
    Have had a Tiagra bb in since 2004 and cover approx 8000Km,s per year. It must have done 30,000 Kms in all at least. By the same token have gone through 4 cranksets,5cassettes and 5 chains and 2 rear mechs.
    Ademort
    ademort
    Chinarello, record and Mavic Cosmic Sl
    Gazelle Vuelta , veloce
    Giant Defy 4
    Mirage Columbus SL
    Batavus Ventura
  • Crapaud
    Crapaud Posts: 2,483
    Bhima wrote:
    It depends on how much pressure you put on it by standing on the pedals climbing, constantly going out-of-the-saddle for sprinting or accellerating from zero on too big a gear. ...
    I nearly put something like that in my last post, but wasn't 100% certain. I'm one of life's spinners so that would explain the extended life of my BB and chain compared to some.

    Do you have any links to something authoritative, Bhima? (I couldn't find anything in my quick search.)
    A fanatic is one who can’t change his mind and won’t change the subject - Churchill
  • Bhima
    Bhima Posts: 2,145
    No links, but it's what i've been told by every single bike mechanic in every single shop i've been in. I had a few dodgy chains recently so got asking questions about component damage/lifespan in a few local shops while searching for the cheapest bargains.
  • ademort
    ademort Posts: 1,924
    Bhima wrote:
    It depends on how much pressure you put on it by standing on the pedals climbing, constantly going out-of-the-saddle for sprinting or accellerating from zero on too big a gear. The same things can affect the stress on a chain too.

    Mine's done just over 5000 miles since December.
    Perhaps that explains why i get so many Kms out of mine. I live in the Netherlands and we have no hills. Am no gear muncher and have a good cadence of +-90 However other parts do wear out frequently, see above post.
    Ademort
    ademort
    Chinarello, record and Mavic Cosmic Sl
    Gazelle Vuelta , veloce
    Giant Defy 4
    Mirage Columbus SL
    Batavus Ventura
  • heavymental
    heavymental Posts: 2,076
    Hmm...and now I notice that I either need a Chrous or Record BB to suit my square taper Record chainset. I think Ambrosio do one to fit too but is that my only other option? I can't just replace the bearings can I?

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