Do I install spacers that came with GXP BB, or not?

rambino
rambino Posts: 45
edited May 2016 in Workshop
I've got a brand new SRAM GXP BB (which I'm coupling with a new 10spd SRAM Red Crankset) which came with 2 x 2.5mm spacers: do I use them or not?

I have a standard 68mm BB shell.

The BB is for both 68 and 73mm shells

The consensus online is that for road bikes I do NOT use the spacers

However, if I go ahead and accept the consensus view, and install WITHOUT the spacers the cranks will not go tight enough...they're far too loose.

Also, my old GXP BB had wider cups meaning...so what does this mean? I had the wrong BB all along ?

ANY IDEAS????

Comments

  • keezx
    keezx Posts: 1,322
    A GXP BB on a road frame with road cranks should NEVER be used with spacers.
    The lefthand bearing is clamped beween the 24 mm part of the axle and the LH crank without any form of preload.
    See SRAM's website.
    Is your frame a normal road frame?
  • itboffin
    itboffin Posts: 20,052
    based on what information?

    I replaced my sram gxp BB last weekend with a new one on a road frame with the 2 x 2.5 mm spacers as per the instructions included in the BB for a road frame
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • itboffin
    itboffin Posts: 20,052
    from the SRAM manual

    Use calipers to measure the bottom bracket shell width of your
    frame.
    68 mm bottom bracket shells require one 2.5 mm spacer on each
    side of the bottom bracket shell.
    73 mm bottom bracket shells do not require spacers
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • rambino
    rambino Posts: 45
    Keezx wrote:
    Is your frame a normal road frame?

    This is my bike: http://www.bikeradar.com/gear/category/ ... -10-37778/

    It's a normal road bike, around 5 years old

    The old stock BB, a 2010 SRAM GXP BB, has noticeably wider cups, by 2mm or so.

    Even with the old wider BB, the SRAM Red crankset suffers from chain rub on the outer 53t chainring when cross chaining.

    I'm not sure what I'm doing wrong
  • rambino
    rambino Posts: 45
    itboffin wrote:
    from the SRAM manual

    Use calipers to measure the bottom bracket shell width of your
    frame.
    68 mm bottom bracket shells require one 2.5 mm spacer on each
    side of the bottom bracket shell.
    73 mm bottom bracket shells do not require spacers

    I know but apparently SRAM made a mistake in their manual.

    This is what practically everyone is saying online in various forums.

    I tried putting a spacer on either side but when i tightened from the NDS the cranks ended up getting so tight they wouldn't spin.

    The only thing that seems to work is if I just have one spacer on the DS....but that just sounds wrong?

    I'm confused
  • itboffin
    itboffin Posts: 20,052
    Bottom Bracket Truvativ Elita, 68mm BSA

    Have a look at the BB shell both sides does it have any paint overlapping the external faces? if so get your LBS to face the shell i.e. scrap the paint off and make sure both sides are flat, then install the greased new BB with a 2.5mm spacer each side and pay attention to the torque settings, if in doubt get the LBS to fit it, its not an expensive job and will make a significant difference to shifting and life of your BB when done correctly.
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • rambino
    rambino Posts: 45
    itboffin wrote:
    Bottom Bracket Truvativ Elita, 68mm BSA

    Have a look at the BB shell both sides does it have any paint overlapping the external faces? if so get your LBS to face the shell i.e. scrap the paint off and make sure both sides are flat, then install the greased new BB with a 2.5mm spacer each side and pay attention to the torque settings, if in doubt get the LBS to fit it, its not an expensive job and will make a significant difference to shifting and life of your BB when done correctly.

    You're right, I think I'm gonna have to go to the LBS before I completely lose my cool and deliberately break something. I also have a new set of Yokozuna brake/gear cables which i need fitting. I predict £100 for those 2 jobs alone.

    Thanks for the help though
  • Bozman
    Bozman Posts: 2,518
    I've yet to use a spacer on a GXP BB, both of my frames are 68mm English thread and there's no play at all when you fit the Red chainsets.
  • keezx
    keezx Posts: 1,322
    itboffin wrote:
    based on what information?

    I replaced my sram gxp BB last weekend with a new one on a road frame with the 2 x 2.5 mm spacers as per the instructions included in the BB for a road frame

    If newer GXP bearings are narrower, a spacer on the LH side makes sense.
    Doesn't make any sense to use a spacer on the RH side, as the axle is perfectly located by the LH bearing.
  • itboffin
    itboffin Posts: 20,052
    I realise reading the manual is not in the man book of cool and is on a par with asking for directions but that's what it says and it works.
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • keezx
    keezx Posts: 1,322
    I will ignore nonsens though.....
  • Bozman
    Bozman Posts: 2,518
    After what has been posted it got me thinking about my bikes, so I had a look around on the net last night and you don't need spacers with a 68mm English thread BB.
    If you use both spacers you start getting problems, if your BB shell is wildly out of spec you might require one but otherwise no.
  • StillGoing
    StillGoing Posts: 5,211
    rambino wrote:
    I've got a brand new SRAM GXP BB (which I'm coupling with a new 10spd SRAM Red Crankset) which came with 2 x 2.5mm spacers: do I use them or not?

    I have a standard 68mm BB shell.

    The BB is for both 68 and 73mm shells

    The consensus online is that for road bikes I do NOT use the spacers

    However, if I go ahead and accept the consensus view, and install WITHOUT the spacers the cranks will not go tight enough...they're far too loose.

    Also, my old GXP BB had wider cups meaning...so what does this mean? I had the wrong BB all along ?

    ANY IDEAS????

    Does logic not suggest that if you are unable to tighten the ND side up to not be leaving any gaps, that spacers should be being used? How big a gap is left? Can it be taken up by one of the wavy washers SRAM provide?
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • captain_tiara
    captain_tiara Posts: 106
    Had same.

    Check my posts in this thread- viewtopic.php?f=40004&t=13060039

    GL.
  • frisbee
    frisbee Posts: 691
    Measure things up, even a ruler or cheap plastic callipers will be accurate enough.
  • rambino
    rambino Posts: 45
    itboffin wrote:
    I realise reading the manual is not in the man book of cool and is on a par with asking for directions but that's what it says and it works.

    If I do what the manual says (which according to most people on cycling forums is incorrect and SRAM got it wrong) and place a 2.5mm spacer either side then the cranks seize up when tightened.

    If I go along with the apparent consensus view that no spacers are needed for a 68mm shell then I can't tighten it enough. There's a gap of 2 or 3 mm.

    However, if I just add one spacer on the drive side then all seems to work fine, but this goes against SRAM's instructions and all advice so far received. It also looks/feels wrong to have a spacer only on the one side.

    I examined the old stock BB in closer detail and, as well as saying GXP, it also says 'XR'. And bizarrely a quick google search confirms that SRAM's 'GXP XR' bottom bracket is designed for tandems, and tandems alone! Why the hell would my bike come with a BB designed for a tandem?

    The cups are clearly wider. It's been a great BB and has served well, but I'll say it again WHY A TANDEM BB?!

    The plot thickens
  • keezx
    keezx Posts: 1,322
    rambino wrote:
    However, if I just add one spacer on the drive side then all seems to work fine, but this goes against SRAM's instructions and all advice so far received. It also looks/feels wrong to have a spacer only on the one side.

    What i said...

    [/quote]
    I examined the old stock BB in closer detail and, as well as saying GXP, it also says 'XR'. And bizarrely a quick google search confirms that SRAM's 'GXP XR' bottom bracket is designed for tandems, and tandems alone! Why the hell would my bike come with a BB designed for a tandem?

    The cups are clearly wider. It's been a great BB and has served well, but I'll say it again WHY A TANDEM BB?!

    The plot thickens[/quote]

    So you have a tandem crank as well, which explains why you cant tighten the crank with a non tandem BB...
    Really weird.
  • rambino
    rambino Posts: 45
    Keezx wrote:
    rambino wrote:
    So you have a tandem crank as well, which explains why you cant tighten the crank with a non tandem BB...
    Really weird.

    So the wider cups make it a tandem specific BB?

    Odd indeed.

    Maybe it was some kind of mistake during manufacturing? The Verenti Millook got great reviews at the time. It's a shame that Wiggle stopped making their higher end bikes. I know they spent fortunes on expensive tooling for the various manufacturing processes involved, so I guess they needed to recoup some of that early investment. The early Verenti's were very good indeed with seriously good prices to match.
  • keezx
    keezx Posts: 1,322
    Does your bike have a wider rear fork than normal (for wide tyres), this might explain a wider crankset.

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