Bottom bracket spacing

Thewaylander
Thewaylander Posts: 8,594
edited June 2012 in MTB workshop & tech
Hola peeps especially Nic :P

Ok just changed from tripple to duel ring, and need to space out my BB a little more (it already uses one spacer drive side). I have a spare larger and thiner spacer in the draw ready. So mmy question as park tools isnt too clear is if i space out the drive side with another larger spacer to stop the chain pulling in 36 - 11 on my set up do i need to space the non drive side?

Just trying to figure it out as i can't find a clear guide to when to space how to space other than try it and see what works approach.

Cheers ladies

Comments

  • nicklouse
    nicklouse Posts: 50,675
    and the cranks are? and the fitting is?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Thewaylander
    Thewaylander Posts: 8,594
    Race face Deus XC 2010,

    Swapped to 10 speed rings that are compatable too, but don't think this makes any difference to BB spacing

    Hope BB

    On my Mondy Dune R 2010

    Been trying to find out my shell width on line as i don't have my bike with at work, but buggered if i can find a tech sheet anywhere :s
  • nicklouse
    nicklouse Posts: 50,675
    which rings are you using. granny and middle?

    and i take it no spacer non drive side.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • The Rookie
    The Rookie Posts: 27,812
    Why do you need to space your cranks out more do you think?

    A triple is set up so the nominal chainline is on the middle ring, when running doubles most people use the middle most and only drop to the granny when they 'have' to, so just leave them where they are?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Thewaylander
    Thewaylander Posts: 8,594
    nicklouse wrote:
    which rings are you using. granny and middle?

    and i take it no spacer non drive side.

    Yarp 26 innner and 36 middle,

    Current spacer drive side mate. non drive flush :)
  • Thewaylander
    Thewaylander Posts: 8,594
    The Beginner wrote:
    Why do you need to space your cranks out more do you think?

    A triple is set up so the nominal chainline is on the middle ring, when running doubles most people use the middle most and only drop to the granny when they 'have' to, so just leave them where they are?
    Because your middle ring is designed to run from about 2-8 roughly smoothly and i need to spend long periods now in 10 on the middle ring if you like.

    Also there is definate pull across from the middle ring in 10 gear.

    Nic knows his numbers dudes a legend on bike mechanics
  • nicklouse
    nicklouse Posts: 50,675
    Thewaylander wrote:
    nicklouse wrote:
    which rings are you using. granny and middle?

    and i take it no spacer non drive side.

    Yarp 26 innner and 36 middle,

    Current spacer drive side mate. non drive flush :)
    not happening with those cranks.

    you have a 73mm BB so there is no movement possible.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Thewaylander
    Thewaylander Posts: 8,594
    How have i currently got a spacer in there then?
  • nicklouse
    nicklouse Posts: 50,675
    Thewaylander wrote:
    How have i currently got a spacer in there then?
    as that is what is needed. but you can not add any more or you will either crush your bearings or have a loose crank. and as there is nothing on the non drive side that you could move over it aint happening.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • njee20
    njee20 Posts: 9,613
    You need one spacer with a 73 shell, as you have, on the drive side. You have no options to move it further outward (as you are trying) because adding any more spacers to the drive side means there's not enough axle on the drive side.

    With a 68 shell you have 2 spacers on the drive side and one on the NDS as standard, so you can substitute the NDS one to move the cranks to the right.
  • Thewaylander
    Thewaylander Posts: 8,594
    Ah i seesaid the blind man to the monkey
  • The Rookie
    The Rookie Posts: 27,812
    Thewaylander wrote:
    [
    Also there is definate pull across from the middle ring in 10 gear.
    So 1x10 never works then? Your middle ring would/should be in the nromal '1x' location.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    In a 1 x 10 setup I'd go for the best chainline for your most used gear or couple of gears if not using a single specific setup up front.
  • njee20
    njee20 Posts: 9,613
    Mine works fine, I'm using the inner ring position on some M985 cranks, which is a slightly narrower chainline than using the middle ring position of a triple IIRC.
  • Thewaylander
    Thewaylander Posts: 8,594
    Cheers for the help,

    Never got the spacing arrangement, then when you said it clicked, test ride went well :)

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