Dura Ace crank arm came off my Cannonade synapse. Advice needed!

vespario
vespario Posts: 228
edited May 2017 in Workshop
Went out on my bike today after mate changed chainrings and the crank arm came off 3 times and wouldn't then go back on. It was moving about and sheered off the plastic locking nut. Have it on now but can't get the locking plate pin in the hole so it protrudes out of the crank arm on the outside.
Have Synapse Hi Mod 2015.
Have wheels BB30 adaptor fitted.
The splines seem a bit flattened but got it all on with some tapping of a rubber mallet.

Weird thing is it has all been fitted for the last 2 years doing about 5/6000 mile plus though mate took apart 4 weeks ago to switch out chain rings.

Do I need a BB30A adaptor instead? Should I replace chainset? Have ordered the plastic locking cap.

Advice from those with experience of Cannonade BB30A greatly appreciated!
Don't need sarcasm - had plenty of banter from my club mates :lol::lol::lol: !!

Comments

  • Ben6899
    Ben6899 Posts: 9,686
    Your mate didn't torque everything up / set preload properly. You've rode with it loose, it's worn the splines and now popped off.

    You might need a new set of cranks. :(
    Ben

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  • Man Of Lard
    Man Of Lard Posts: 903
    As ben6899 says, your mate has ballsed it up and you've compounded the balls up.

    If you can't get the locking pin to lock, you're looking at a new set of cranks (although it's probably cheaper to buy a new crankset including chainrings)
  • vespario
    vespario Posts: 228
    Cheers guys!
    The lock bit wouldn't go in after he took it off to regrease yesterday.

    He did tighten with a torque wrench but maybe not tight enough.

    Could the BB30 adaptor be an issue?

    Do I need chainset and a different adaptor?

    Thanks for feedback! :D
  • Man Of Lard
    Man Of Lard Posts: 903
    vespario wrote:
    Cheers guys!
    The lock bit wouldn't go in after he took it off to regrease yesterday.
    This is the key to your disaster.
  • vespario
    vespario Posts: 228
    Man Of Lard wrote:
    vespario wrote:
    Cheers guys!
    The lock bit wouldn't go in after he took it off to regrease yesterday.
    This is the key to your disaster.

    What is the solution?
  • Man Of Lard
    Man Of Lard Posts: 903
    From your description, most probably a new crankset. Possibly a new/different bottom bracket (if the one you have doesn't allow the locking arm to engage). Definitely a different mate to do your maintenance :)
  • flasher
    flasher Posts: 1,734
    If the lock pin wouldn't locate then the drive side wasn't pushed far enough through the bb.
  • vespario
    vespario Posts: 228
    Flasher wrote:
    If the lock pin wouldn't locate then the drive side wasn't pushed far enough through the bb.

    It is fully pushed in wondering if having a BB30 adaptor and not BB30A is the problem.
  • sungod
    sungod Posts: 17,338
    if the frame is bb30a and you are using a bb30 adaptor, it may well be that the crank arm has not been as far onto the splines as it should have been...

    bb30a has an asymmetric 73mm bb shell, the non-drive side is 5mm wider wrt. to the centreline of the bike

    to compensate, the wheels bb30a adaptor extends outboard on the drive side, but is flush on the non-drive side...

    bbright_1.jpg
    my bike - faster than god's and twice as shiny
  • svetty
    svetty Posts: 1,904
    Did your mate fit the adaptors to the wrong sides??
    FFS! Harden up and grow a pair :D
  • fenix
    fenix Posts: 5,437
    This is a LBS size issue.
    Clearly you can't do it - or you'd not have let your mate do it.
    Clearly he can't be trusted....
  • keef66
    keef66 Posts: 13,123
    If your mate just took off the chainset to fit new rings and didn't do anything to the bottom bracket it should all have gone back together like it was for the previous two years. Shimano chainsets are like Duplo; a 3 year old could install one.

    If he couldn't get the pin on the locking tab to drop into the hole in the spindle it suggests it wasn't on properly so he shouldn't have been swinging on his torque wrench.

    How much do you value his friendship? Is he likely to admit his error and buy you a new DA chainset??
  • Man Of Lard
    Man Of Lard Posts: 903
    I agree with keef66 - and its why I have a rubber mallet in my toolchest - to take away that last "bawhair of uncertainty" over whether it is fully home or not.
  • Bobbinogs
    Bobbinogs Posts: 4,841
    keef66 wrote:
    ...

    How much do you value his friendship? Is he likely to admit his error and buy you a new DA chainset??

    I certainly wouldn't be following this kind of thing up with the mate. I figure that if I help anyone out for free then it is on the proviso that they accept the risk, not me.
  • dwanes
    dwanes Posts: 954
    Take the whole thing to an reputable/ experienced / knowledgeable bike shop and face up to the costs.
    Don't let you or your mate or anyone on here to advise you to do any more messing with it.

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