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  • This topic has 27 replies, 14 voices, and was last updated 2 months ago by Yak.
Viewing 28 posts - 1 through 28 (of 28 total)
  • Which crank now?
  • reeksy
    Full Member

    My XTR M9000 crank spindle has scored fairly badly (0.2mm) where it’s run on the Hope bearings, such that it has an annoying amount of play.

    What should I replace it with? Ideally without replacing the BB as well, so 24mm spindle.

    Don’t want to spend silly money but prefer it doesn’t happen again two years later.

    twonks
    Full Member

    Not entirely sure what you mean – but does it suggest the bottom bracket is not round, has a spur etc rather than the cranks being bad?

    I run XTR 9000 cranks in a Hope btm bkt and it has been fine for 3+ yrs, although that bike hasn’t been used much. The same btm bkt however was transferred from my previous builds and has had about 8 years riding with no problems.

    For a new crank I’d be looking at whatever Shimano I could get at the right price – above SLX.

    reeksy
    Full Member

    The Hope bearings run directly against the crank spindle. My non drive side bearing has scored the spindle such that it now moves… hard to explain without a photo.

    d42dom
    Full Member

    if the bearing has worn into your BB axle then there will be some misalignment most likely in the BB shell of the frame, worth checking that out as otherwise in time you’ll be in the same situation again.

    reeksy
    Full Member

    It’s the same as this:

    Worn hollowtech axle?

    pipm1
    Free Member

    I had this happen a bit on my XT cranks in a Hope BB. I went back to a Shimano BB.
    Shimano plastic top caps on their BB cups seem like a good idea. Aluminium spindle in a steel BB race doesn’t seem so good.

    Edit: i only found the login box now after the redesign, seems odd being way down the bottom.

    rootes1
    Full Member

    Does the XTR crank have a aluminium alloy axle? Thought perhaps it was steel like XT etc?

    have you a push fit Hope BB or a screw in BSA?

    the plastic bits on Shimano BB are there by design.

    if using a BB were the bearing/axle run direct I would be using a thin smear of low strength engineering adhesive such as Loctite Bearing Fit (and allow it to fully cure before riding)

    sillyoldman
    Full Member

    Shimano axles are cromo, so less prone to this issue than 30mm Alu axles, but any axle running directly on a bearing inner race is at risk of wear. Shimano BBs have the plastic top hats for this reason.

    rOcKeTdOg
    Full Member

    Ingrid

    reeksy
    Full Member

    Ingrid are 30mm only afaik

    noeffsgiven
    Free Member

    I never thought it was a good idea to have direct axle contact with the bearing, the slightest bb shell misalignment can lead to scoring or reduced bearing life. The reason some people get a short life out of a bottom bracket is down to this just as much as dirt n water ingress.
    I’d switch to a bb with plastic tophats.

    didnthurt
    Full Member

    This will probably be unpopular but I’d go with a SRAM one.

    I’ve had more Shimano cranks fáil ón me in the past than SRAM.

    Yak
    Full Member

    GXP is fairly tolerant of a bit of misalignment. (although I have not used them with a hope bb though. you will need an adaptor).
    So is HT2 with the HT2 bb inc the plastic top hats.

    chakaping
    Free Member

    Sell the Hope BB and replace with a Shimano one and an SLX chainset.

    They are a very reasonable weight and have the best fastening system, as you know.

    reeksy
    Full Member

    I got the Hope BB for both bikes cos I was munching through Shimano ones so fast. Aaaaaand, the first Hope BB came with GXP adapters so I sold them on.

    Ah the irony.

    vmgscot
    Full Member

    Been using RaceFace Aeffect in my Hope BB for a few years – might be seen as a downgrade on XTR though!

    reeksy
    Full Member

    I’ve been looking at RaceFace, Middleburn, and a second hand good set of XTR9100s today. Or ditching the BB and trying a new set of 30mm whatever. There’s too many choices!

    Yak
    Full Member

    Don’t go 30mm if there’s misalignment in the bb. Stay 24mm, or if you want ultimate reliability, swap to square taper with a shimano sealed BB.

    steve_b77
    Free Member

    Sell the Hope BB and replace with a Shimano one

    This as there’s no way a BB bearing should be wearing out a crank axle, I’d suggest the Hope BB is at fault here.

    Yak
    Full Member

    Is the crank spindle worn evenly or is it worn more on one side?

    chakaping
    Free Member

    Sod it, I reckon it’s new bike time.

    JonEdwards
    Free Member

    I’ve been using Shimano cranks and Hope BBs across multiple bikes doing big miles for the best part of 15 years now. First I’ve heard of this.

    Can’t help but feel that if the crank can move independently of the inner race of the BB bearing, you’ve got bigger issues that just a worn crank, and just swapping the BB and/or cranks isn’t going to solve them. has the frame ever been properly chased and faced?

    As a (very) bodge solution – bearing fit compound?

    reeksy
    Full Member

    Sod it, I reckon it’s new bike time.

    tempted.

    Is the crank spindle worn evenly or is it worn more on one side?

    More on NDS. I’ve rubbed it back with emery paper and oil.

    has the frame ever been properly chased and faced?

    Only from the factory. I just clean out the threads any time the cups are out.

    chakaping
    Free Member

    Worth asking Hope for their opinion on the cause?

    reeksy
    Full Member

    I sent an email to them earlier. They’ve just replied suggesting a bearing fit compound (think I might have some actually) or shaft replacement.

    Father in law suggested turning down and shimming.

    Yak
    Full Member

    Is the crank spindle worn evenly or is it worn more on one side?

    More on NDS. I’ve rubbed it back with emery paper and oil.

    Sorry, I meant is it asymmetric on the spindle at the wear area?

    reeksy
    Full Member

    Oh, no it’s all round.

    Yak
    Full Member

    Ok. Well given your crank is worn already, then bearing fit is worth a temporary fix. Then probably go shimano again (any) with the shimano bb.

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