BB shell size-Race face BB conversion kit 83mm-advice please

l00cas
l00cas Posts: 75
edited February 2009 in MTB workshop & tech
I just got a new DH frame and it has an 83mm shell case, the BB in my current frame is 73mm, does the race face bb conversion kit 83mm make a 73mm BB fit in an 83mm frame? I tried to read up about it on two websites but they both completely contradicted each other. One said it made the bb smaller and the other said it made it bigger?
If I do use this, can I keep the same cranks or do they need to be changed to fit the bigger shell size?
cheers
L

Comments

  • nicklouse
    nicklouse Posts: 50,675
    what cranks do you have.

    if ISIS fitting new bb but you can use your cranks.

    X type new cranks and new bearings.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • l00cas
    l00cas Posts: 75
    Hi nick, thanks for the info I wasn't really trying to get at info about the cranks, what I meant to say really was does the raceface convertor allow you to fit 73mm bb's to a 83mm bb frame or vica versa?
  • nicklouse
    nicklouse Posts: 50,675
    So what are the cranks?

    Race face do make more than one crankset and they do also have more than one fitting.

    each needs a different solution.

    Oh and link to this converter as it may explain what crank fitting you have.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • l00cas
    l00cas Posts: 75
    The cranks are unbranded/stock shimano that came with the bike, but im pretty sure theyre square taper. the links here: http://www.chainreactioncycles.com/Mode ... delID=8243
  • nicklouse
    nicklouse Posts: 50,675
    well that is just the spacer to go between an X type RF bearing set. to space it from 83mm to 68/73mm. to be used with a 68/73mm spec RF crankset.

    so you will need new RF cranks for you old frame to use the new bearings with the adaptor.

    (shimano HT2 cranks will also work but they do normally come with bearings already).
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • l00cas
    l00cas Posts: 75
    ok so its basically to allow you to use a certain type of crank? Thanks for clearing that up, I thought it was to alllow you to use 68/73mm BB's on a frame with an 83mm bb shell.
    cheers
  • nicklouse
    nicklouse Posts: 50,675
    Ok now you are confusing things again.

    what are you wanting to use on what?

    Where i was in the understanding was you want to fit the X type bearings in you old frame?
    yes they will fit but you will need that new spacer as the fitted on is too long. you will also need compatible cranks.

    If you want to use you old cranks on the new frame?

    new bb will be needed (dont think there are any to suit your cranks though).
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown

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