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I need some help identifying my bottom bracket. One of the bearings is in a very bad shape and needs to be replaced. Bottom bracket photos

  • Take the failed bearing cartridge to an electric motor bearing dealer near you and see if they can't fix you up. There should be such a place in any town of 20K people or so. – Daniel R Hicks Oct 1 '14 at 1:38
  • I had a hard time removing the bearings (even damaged one of them in the process. (it was already broken)). I guess it will be really hard to put the new ones in the driveshaft and I don't want to damage those. I'll buy a whole new bottom bracket. – Bruno Camarneiro Oct 1 '14 at 16:51
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It appears to be a standard square drive sealed cartridge type bottom bracket. It looks as if it came apart. Normally the bearings are not removed from the shaft but are removed and replaced as an assembly. If you measure the width of the frame where the bearings were removed you should measure 67mm or 73mm. Measure the length of the square driveshaft. The length will vary depending on the bike type, drive train etc. The other option is English or Italian thread. Most likely it is English but you can't tell from the photos. The options are to look on-line for a bottom bracket that matches your measurements or bring all the pieces to your LBS (local bike shop) and have them measure and match to something in your price range.

  • I don't think it came apart -- I think it was made in pieces like that. The individual bearing cartridges are replaceable. – Daniel R Hicks Oct 1 '14 at 1:39
  • While they can disassembled the shell shaft and bearings will typically come out and are sold as an assembly. – mikes Oct 1 '14 at 10:31
  • I've seen BB cartridges before, and the pictures look nothing like those. And I've never seen a BB cartridge that looked like it was designed to be disassembled. – Daniel R Hicks Oct 1 '14 at 11:43
  • It was really hard to disassemble the bottom bracket (specially removing the bearings). As one of them was already broken I had no fear of damaging them. I guess it will be really hard to assemble the new bearings too. Maybe buying the whole bottom bracket is the best thing I can do. – Bruno Camarneiro Oct 1 '14 at 16:57
  • btw, the frame measures 67mm. That matches the 3P code in the link from @sessyargc.jp answer – Bruno Camarneiro Oct 1 '14 at 17:00
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It's a generic BB. The 3P code on the spindle is a clue to the size.

http://www.sheldonbrown.com/bbsize.html

Sealed cartridge BBs are ridden until they fail (ie bearing disintegrates, like in your case) at which point you buy a new BB unit. You can try just getting the bearing (but IME it can be a frustrating endeavour). There should be numbers on the bearing face jot those down and visit a parts/auto shop or have our LBS order (if they can). Most parts/auto shops will have a compatibility chart of bearings between brands.

For example here's a link showing how to identify an SKF bearing http://www.skf.com/group/products/bearings-units-housings/super-precision-bearings/double_direction_acthbb/marking-on-bearings/index.html
If you can't find a compatible bearing you have no option but to buy a new BB unit.

  • It matches the 67mm frame. Thanks! I'll vote up all the answers when I get to 15 rep – Bruno Camarneiro Oct 1 '14 at 17:02

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