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Choosing a new bottom bracket

robgriffin247robgriffin247 Posts: 22
edited June 2012 in Workshop
I don't know if this has been answered before but I tried looking and found nothing.

I've just had a bottom bracket replaced in one of my bikes, I left it in the local bike shop for them to repair because it is something I have never done. But this got me thinking, (I have another bike with a BB that is nearing its end) so next time I need to replace one I'd like to have a crack at it my self, I can do all other maintenance my self so I feel like the BB is my weakness!

The problem is I have no idea how to choose a new one - obviously there are a lot of options but I don't know what I can and can't use. Currently it has a Shimano SM-BB4600 (68mm British), attached to a 2010 Specialized Allez Sport Triple. So perhaps someone can give me pointers on what attributes to look for... basically what do I have to make sure is the same when I pick the new one to make sure it is compatible?


  • estampidaestampida Posts: 1,008
    is it an exo or an isis?? or even push fit...

    exo - hope technology for bling

    have a look but the cheapest is prob ... h0ogrfeo87
  • jermasjermas Posts: 484
    You need a Hollowtech 2 compatible bottom bracket (English thread).
    Personally I'd upgrade to Shimano 105 (SM BB 5700) which have better bearings and slightly better seals.
    Shimano Ultergra and Dura-ace will also fit but they cost more. Hope bottom brackets are also a good option but they're more pricey.
    You will need a bottom bracket tool to remove/replace the cups. Also anti seize grease should be used on the threads when it's installed. It's a straightforward job so good luck.
  • Bike-RichBike-Rich Posts: 275
    Sorry to thread hi-jack but this is something I will be doing soon also :)

    Just ordered a combo bracket remover tool with the plastic socket bit too (Hollowtec),

    2 questions, what type of greese should I use? Waterproof? I have some 'copper anti seize' stuff here - is that any good?

    And, what bottom bracket would make a good upgrade - you mention the Shimano 105 - I have made a note of englsih thread only. I see there are a few sizes also - how do I know what I need?

    Kind regards,
  • keef66keef66 Posts: 13,123
    Any old grease or indeed the copper anti-sieze stuff. It's just to make removal easier next time.

    The 105 external BB cups should only come in one size, and a choice of English or Italian thread. Most require the former. Some places still have the earlier 5600 version, but most are 5700 now. Doubt there's any difference
  • southdownswolfsouthdownswolf Posts: 1,514
    Shimano instructions: ... 746319.pdf

    As has previously been said, as long as it is Hollowtech II, and the correct thread- British or Italian, then any BB can be used.
  • Bike-RichBike-Rich Posts: 275
    Thanks guys,

    Is there one which stands out as being good/popular though (within budget of £30)?
  • keef66keef66 Posts: 13,123
    CRC had Ultegra ones for £20 last time I looked. Can't say fairer than that
  • Bike-RichBike-Rich Posts: 275
    Thank you,

    Will let you know how the install goes :)
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