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Campag/Shimano Bottom bracket

Discussion in 'Bicycle Mechanics and Repairs' started by llllllll, 5 Dec 2007.

  1. llllllll

    llllllll New Member

    The bearings in my BB have just gone, it's a Shimano UN53 and it's less than a year old :smile: . This isn't the first time I've had problems with Shimano durability, so I'd rather not buy another. Can I use a Campag BB (square taper) with Shimano cranks, I know they've got slightly different tapers but I've heard they can work one way around, just can't remember which. Otherwise can anyone reccomend a (cheapish) none Shimano BB that works with Shimano road cranks?
     
  2. Tim Bennet.

    Tim Bennet. Entirely Average Member

    Location:
    S of Kendal
    That's odd. Generally the Shimano square taper BBs have a reputation for being pretty reliable and excellent value for money. The only negative things I've heard is they do break if you're into taking jumps bigger than 6ft or so.

    I have UN72s in the moutainbikes and UN53s in the tourer and commuter. I certainly get more than a couple of years use out of them all. The Campag in the race bike doesn't get anything like the beating of the others, so its hard to compare. However I've tried loads of other makes, and Shimano Square Tapers have always been so much more reliable than the so called 'improved' designs.

    For the money I would either continue to replace the UN53 as and when necessary or try a UN72.

    Other things to check: Do you have a drain hole in the bottom of your BB shell? Do you smother it in cheap car grease when you fit it? Apart from that I can't think of why you are having problems with what I've always thought of as one of the only truly 'fit and forget' items on a bike.
     
  3. barq

    barq Senior Member

    Location:
    Birmingham, UK
    I tend to agree with Tim's comments. I have a friend who destroys BBs, but I think that is down to the way he pedals and heavy use in conditions where the BB is frequently submerged in water. Unless you are going to start considering external bearings (with all the implications that may have for your choice of chainset), I'd replace like for like.
     
  4. yenrod

    yenrod Guest

    I had a shimano BB for 15yrs - the bike snapped 1st :smile:
     

  5. you are right the un72 is better then the un53 but the campag are better still you need to make shore that the square taper is the same as there is 3 tipes a standard square, suntore square witch is the same but the pich of the taper and a diamond.


    why dose the drain hole matter if its a sealed BB no water can get in the BB can it?.
     
  6. OP
    OP
    llllllll

    llllllll New Member

    It's got a drain hole, and I'm not big so I'm not putting huge power through the pedals. It is kept outside and used pretty much everyday, but even so 1 year isn't long for BB, it's not as if it's some superlight race job.
    My first road bike was Shimano equipped, the hubs had to go back to the dealer twice in the first year, they did fail again but I gave up and bought a set of factory wheels. One of the pedal fell out of the cranks stripping the threads and the STIs disintigrated just a week outside of the warrenty. I gave up after that and bought a Campag equipped bike. Unfortunately I had another Shimano chainset lying around so when I built up my commuter I bought a Shimano BB to fit and again the Shimano part doesn't last. So I'm not buying Shimano - sorry. I have got a set of Campag cranks somewhere so if need be I'd rather get some chainrings and a Campag BB.
     
  7. Tim Bennet.

    Tim Bennet. Entirely Average Member

    Location:
    S of Kendal
    Sealed Bearings' (IIRC) only means they are pre assembled with their own races and you won't have to put them from either loose balls (or captive one in races) or adjust them for end float. These 'sealed bearings' are used in lots of headsets for instance, but although the plastic cover does afford some weather proofing, its not perfect. When they 'feel rough' you can dig the cover out and find the insides are gone completely rusty.

    It's true, the whole BB assembly will also have seals on them, but again they are not perfect and the less assaults they have to repel, the longer their life. A drain hole prevents them sitting in a water bath.

    Proof that crap does get into them comes from the fact the bearings have failed. The speed of rotation and load is unlikely to put it under much stress.