Viewing 13 posts - 1 through 13 (of 13 total)
  • Help needed please– XT m770 crankset
  • iain65
    Free Member

    I have what I think is an unusual problem, a clicking noise on the down-stroke of the pedals coming from the drive side when out of the saddle (near the bottom of the pedal stroke). Now the thing that I thought of first was the BB, then the pedals – changed both and still clicking, then I started changing every other related part on the bike; wheels, rear mech, chain – still clicking.

    Today I moved the crankset onto another bike and lo and behold, it’s clicking on the other bike.

    Therefore all I can assume is that it’s the crankset, it clicks in all 3 rings so it’s not bolt related and there are no obvious witness marks on the cranks/rings where it might be catching something.

    So, the only conclusion I can come to is it’s the interface between the steel axle and the alloy cranks – has anyone ever heard of this being a problem or has anyone had a similar problem?

    Advice gratefully received because I’m a bit lost now!
    Thanks,
    Iain

    gee
    Free Member

    Are the pedal threads spotless and greased?

    Is the axle spline and the lh arm spline spotless and greased?

    antares
    Free Member

    Sorry i cant be of any help but I have the same problem with my M785 cranks. Started a couple of weeks ago and I’ve tried most of the things you have apart from trying them in another bike. I’m a bit stumped myself as to what’s causing it so will be interested to hear other people’s views on it.

    iain65
    Free Member

    Hi Gee, tried three different sets of pedals but not fully cleaned the threads on the cranks, will try that and the spline on the axle, thanks, good advice.
    Antares, will let you know if I get a solution.
    Cheers
    Iain

    gee
    Free Member

    Also remove the rings, clean the interface and bolts, grease.

    doncorleoni
    Free Member

    Got exactly the same issue with a brand new set of slx triple cranks….installed and clicked every rev with slight load in all 3 rings. Right, first I thought must be dry pedal threads – cleaned, greased and back. Click still there. Ok, so moved onto bb undid the old xt one, cleaned chased threads, greased and installed new slx BB.

    Click still there, swapped pedals, click still there, stripped pedals and regressed bush and bearings….click still there.

    So then thought I would torque up the chain ring bolts to 60-70 Nm as per guide. They were around 20 straight out the box…..click still there.

    So my next step is to do as gee suggested – remove bolts & rings and clean interface. Maybe a bit of dirt/swarf is trapped between ring interface or maybe it’s the threads running dry on ring bolts. From looking at the drive side crank to axle interface – it looks like a splined interference press fit. I doubt this is the cause.

    If you sort it let me know and likewise I will do the same! It’s annoying!

    big_scot_nanny
    Full Member

    I would try new bolts in the non drive side crank, replacing the ones that hold it onto the axle. That was what it was on an old bike of mine, which took a lot of diagnostics to uncover!

    HTH

    Kev

    iain65
    Free Member

    Thanks, that all sounds sensible, I think the ultrasonic wash at work may be getting used and a set of new bolts!

    iain65
    Free Member

    Good news (so far), I stripped the crankset, cleaned everything meticulously and put it back together and it’s stopped clicking, yippee!

    Hopefully it will stay like that way for a while!

    Thanks again for all the help.
    Iain

    Ps did not change the bolts.

    antares
    Free Member

    Mine got another thorough clean last Wednesday but I didn’t ride it until Sunday and the clicking on mine had gone as well 🙂

    iain65
    Free Member

    Brilliant! Good result all round 🙂

    antares
    Free Member

    Quick update on things. After the clicking had gone I went on holiday so didn’t ride the bike for a couple of weeks. First ride out on Tuesday night I noticed a crack in the frame right on a weld. Took it back to where I bought it and they confirmed it was cracked and a replacement is on its way. Maybe the clicking/creaking on mine was down to the frame starting to crack and when it’s cracked right along the weld the clicking/creaking stopped.

    iain65
    Free Member

    Oh bad luck, mine seems to be fine still. I did suspect the frame for a while as its a pretty skinny carbon HT but it still seems to be the cleaning that’s worked.
    Iain.

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