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Crack on drive side Ultegra crank: fixable?

  • 09-06-2021 7:32pm
    #1
    Registered Users Posts: 998 ✭✭✭


    Hi!
    I hope you are well.
    I found a decent crack on the inner side if an Ultegra crank.
    I will attach a picture.
    Do you think it is fixable?

    Thank you!


Comments

  • Registered Users Posts: 7,813 ✭✭✭cletus


    Arequipa wrote: »
    Hi!
    I hope you are well.
    I found a decent crack on the inner side if an Ultegra crank.
    I will attach a picture.
    Do you think it is fixable?

    Thank you!

    It could be welded. It's aluminium though (I assume), which is difficult to weld. If you know a good tig welder, it could be fixed. Otherwise, I'd say no


  • Moderators, Category Moderators, Arts Moderators, Sports Moderators Posts: 48,009 CMod ✭✭✭✭magicbastarder


    i wouldn't ride that again. it could be fixed, i guess, but i'd never trust it.


  • Registered Users Posts: 998 ✭✭✭Arequipa


    Thank u!
    Thats what I was thinking..
    Time for a new crank methinks.....


  • Registered Users Posts: 310 ✭✭Dowee


    I had a crank snap once, it wasn't pretty. One of those "why am I suddenly lying in a heap on the ground?" moments.

    Thankfully it was as I was taking off at a set of pedestrian / cycling lights so the damage to me and pride was limited.

    I'd definitely replace it.


  • Moderators, Category Moderators, Arts Moderators, Sports Moderators Posts: 48,009 CMod ✭✭✭✭magicbastarder


    you were clearly putting too much power out.


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  • Registered Users Posts: 3,119 ✭✭✭T-Maxx


    That chainring needs replacement in any case.:eek:


  • Registered Users Posts: 902 ✭✭✭nicksnikita


    That’s a known flaw on a Ultegra cranks. Contact Shimano and they may replace it free of charge


  • Registered Users Posts: 998 ✭✭✭Arequipa


    Thanks for the replies..
    I contacted Shimano & there is only a x2 year warranty.. so i am definitely out of warranty...

    As u mentioned too.. there is a lot of wear on the crank anyway....


  • Registered Users Posts: 485 ✭✭benneca1


    Arequipa wrote: »
    Thanks for the replies..
    I contacted Shimano & there is only a x2 year warranty.. so i am definitely out of warranty...

    As u mentioned too.. there is a lot of wear on the crank anyway....
    Not a warranty issue id say reasonable use you’d expect longer I would get back I had the same crap once over a different issue but they eventually sorted me


  • Moderators, Category Moderators, Arts Moderators, Sports Moderators Posts: 48,009 CMod ✭✭✭✭magicbastarder


    That’s a known flaw on a Ultegra cranks. Contact Shimano and they may replace it free of charge
    that's not the usual failure i've seen attributed to ultegra crankset failure i think; usually you hear of the spider failing.

    https://www.bikeradar.com/features/shimano-crank-failure/


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  • Registered Users Posts: 902 ✭✭✭nicksnikita


    that's not the usual failure i've seen attributed to ultegra crankset failure i think; usually you hear of the spider failing.

    https://www.bikeradar.com/features/shimano-crank-failure/

    True...still though

    Unless it’s been impacted it shouldn’t be failing there


  • Registered Users Posts: 2,683 ✭✭✭triggermortis


    I had Ultegra 6800 crank delaminate on the drive side, but not crack where yours has. Its a 2 part piece that's basically glued together in a box section, but yours has split across the section.
    I would not ride that anymore and replace as soon as possible.
    It's probably not an issue for you seeing the state of the outer ring there, but if you get an 8000 series replacement, the 6800 rings will not fit (maybe the inner might, but the outer definitely won't) as I learnt from experience


  • Registered Users Posts: 998 ✭✭✭Arequipa


    Thank you for the replies..
    I suppose when we ask for lighter components... they will eventually wear out or fail..

    When the crank cracked... I couldnt tell for a while... there was a slight creak and a slight movement in the right pedal...
    These shimano spd pedals are actually seized to the crank... a long story... I rode them through x2 winters and not enough grease.. so I will need new pedals..

    This is the crank I am going for, if any of you are interested... Trace Velo of youtube fame, highly recommends them:

    https://www.aliexpress.com/item/1000006338700.html?spm=2114.12057483.detail.3.79b82b6fYCuego

    I am buying a spare chainrings, which bolts onto the crank arms.


  • Registered Users Posts: 14,230 ✭✭✭✭ednwireland


    if your getting new cranks anyway id get a small blowtorch and heat the pedal crank could be enough to break the seal. (obviously dont get the things glowing but a heat cycle could free them)

    if not aluminum cranks are easy to cut with a hacksaw :D


  • Registered Users Posts: 998 ✭✭✭Arequipa


    Thank you edinireland..

    Might give that a go!


  • Registered Users Posts: 24,937 ✭✭✭✭Wishbone Ash


    cletus wrote: »
    It could be welded. It's aluminium though (I assume), which is difficult to weld. If you know a good tig welder, it could be fixed. Otherwise, I'd say no
    It would be a lot cheaper and way more effective to simply fit new cranks than pay a specialist to try a repair job.

    I know it has been mentioned already but the wear on that chain ring? Jesus, how can you ride a bike in that state? :eek: Is your chain not slipping under any pressure?


  • Registered Users Posts: 43 GabbaTheHutt


    A known fault with ultegra cranks unfortunately :(
    Cracking starts there and then can result in the spider giving way too. Know 3 people it happened to - one ended up with the crank end attached to his shoe but not the bike

    With the chainring that bad replace the whole chain set - if rings were good you could replace the crank only


  • Registered Users Posts: 8,615 ✭✭✭grogi


    True...still though

    Unless it’s been impacted it shouldn’t be failing there

    Even if it shouldn't fail and it indeed had material defect. That's exactly what warranty is for - to cover you for such defects for a given period of time.


  • Registered Users Posts: 7,813 ✭✭✭cletus


    It would be a lot cheaper and way more effective to simply fit new cranks than pay a specialist to try a repair job.

    I know it has been mentioned already but the wear on that chain ring? Jesus, how can you ride a bike in that state? :eek: Is your chain not slipping under any pressure?


    Absolutely. The question, though, was could they be fixed. I was just trying to point out that a fix is definitely possible, but would be difficult. Perhaps I should have spoken to cost, but that's up to the OP.

    Could be that a friend of his is an excellent Tig welder (one of mine is)


  • Registered Users Posts: 24,937 ✭✭✭✭Wishbone Ash


    cletus wrote: »
    Absolutely. The question, though, was could they be fixed. I was just trying to point out that a fix is definitely possible..
    In fairness, you are correct - that was the question that was asked. I suppose I was thinking along the lines that, when 99% ask if something can be repaired, it's usually to avoid buying a new one.


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  • Registered Users Posts: 105 ✭✭PringleDemon


    There's an entire Inst page with all sorts of failures

    https://www.instagram.com/thanksshimano/


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