Torquing Bottom Bracket.

wilkij1975
wilkij1975 Posts: 532
edited November 2011 in Workshop
I think I know what the answer will be to this but here we go!

Is it essential to torque your bottom bracket when fitting? I was going to buy the tool that goes on a socket wrench / torque wrench but my wrench doesn't go as high as the required BB torque.

Comments

  • There's no doubt a torque wrench will do the job right, and easier. But you can survive without one, i did my FSA BB by hand a with a HT2 wrench a few months ago. Just do it up bloomin tight. (i think i used a mallet as well)

    Another issue i realised is the Shimano HT2 wrench is thin...and its not easy to apply that much pressure without making it uncomfortable on the hands. Thats why i think the socket type wrench is much better, even if you're just using a ratchet or whatever, much easier to apply decent pressure.

    Anyway, with a wrench, mine hasnt come loose.
  • k-dog
    k-dog Posts: 1,652
    I got a torque wrench for the first time last year - and it's a great thing to have - for bb's and for cassette lockrings.

    What surprised me more is that 50 or 40Nm is actually a lot less than what I would have thought - so just doing it really tight isn't actually what you want to do.

    I have a big one that does 30-150 or something and a small one for small stuff. Seem to do the job between them.
    I'm left handed, if that matters.
  • Thanks for the info guys.

    I think i'll invest in a socket wrench type tool. I have used the standard HT2 tool but only for removing and, as you say, it is a bit thin and it also slipped and broke my BB (MTB). Can't stretch to a higher torque wrench yet though.
  • It's a difficult one... normally you don't need a torque wrench for high Torque values like 40 or 50 Nm... you might for low ones, as it's easy to over torque fragile carbon bits.
    However, if you have a "feel" for threads, your arm is as good a torque wrench as a proper one, if not better... if you don't have a "feel" for threads, then by all means, get the torque wrench.
    It's easier to have a feel if you use the appropriate size tools , as they give you the correct leverage you need... big for big torque, small for small torque. Don't use a massive 1/2 inch socket ratchet to do a small nut, as you'll probably break it. Conversely, don't use a T shaped Allen key if you have to do a 10 mm one, as you don't have enough leverage.

    Personally I have never overdone or underdone a thread (never broke, never came loose), hence I am arrogant enough to think I don't need one... :twisted:
    left the forum March 2023
  • Fair play to you Ugo! I have never over done anything either.........yet!

    I just wonder why they sell BB tools that can't be used with a torque wrench e.g a standard HT2 tool if the torque of the BB is really imprtant?
  • wilkij1975 wrote:
    Fair play to you Ugo! I have never over done anything either.........yet!

    I just wonder why they sell BB tools that can't be used with a torque wrench e.g a standard HT2 tool if the torque of the BB is really imprtant?

    It's not that important... it is a matter of liability, as in every aspect of life. Shimano (or Campagnolo) doesn't want to be responsible if you die because your BB comes loose, so they advise on what is the correct setting. Personally I have never used a Torque wrench on a BB and I have used a range of BB from classic cone and ball ones, all the way to Hollowtech 2 and Ultra Torque. I have never had a loose BB... not a British thread, not an Italian thread.
    The advice is do it tight, don't overtighten by using your body weight... if you are scared of having it undone, use a mild thread lock, but I'd rather use just an antiseize, copper paste from Halfords is still the best
    left the forum March 2023