Thread stripped from crank arm, what are my options?

loz_the_guru
loz_the_guru Posts: 33
edited July 2013 in Workshop
So due to me putting a falt pedal on for a qucik ride in a botched way, i've stripped the thread from one of my crank arms where it attaches to the pedal. I'm struggling to find a replacement crank arm, as ideally i'd rather not repalce the whole drive train. Can anyone offer me any advice as to what my options are?

The crank arms at the moment are 175mm Truvulo ones, which attach to the chain ring at 5 points. I've uploaded a picture which might help, any thoughts?

I've looked at buying something like this http://www.chainreactioncycles.com/Models.aspx?ModelID=105748, but presumably its not as simple as straight swapping the crank arm?

Comments

  • ugo.santalucia
    ugo.santalucia Posts: 28,325
    A good LBS might be able to re-tap your crank arm.

    Alternatively, you are looking at a new chainset, as typically crank arms are not sold alone. They ned to match your existing bottom bracket, otherwise you are looking at a new BB too
    left the forum March 2023
  • nicklouse
    nicklouse Posts: 50,673
    as above a good bike shop will be able to fix it.

    lots of kits available to sort it.

    but your rings do look a tad worn so maybe take it as time to replace the cranks as a whole.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • imposter2.0
    imposter2.0 Posts: 12,028
    The chainset in that link is a single ring BMX chainset - you don't want one of those. Re-tapping is pointless as the thread has already stripped and there will be nothing to re-tap. Unless you can find someone who can helicoil or timesert, your best option would be to replace the entire chainset. BB looks like it might be square taper, so finding a chainset from Stronglight or similar will not be difficult.
  • vorsprung
    vorsprung Posts: 1,953
    You can buy a cheap complete chainset for 20 quid or less
    You will also need the specialist tool for removing the crank bolts, if you don't already have it
  • Brilliant replies guys, thanks a million! The thread is pretty much completely stripped, so a new chainset is in order I think. Can anyone give me a better idea of what i'm searching for? I know I need a triple, but how do I work out the number of teeth I have on each ring (and does it have to match exactly?). Also, how can I check if the BB is indeed square taper or not? Finally, could anyone give me an idea of the tool I will need to swap it all out?

    Thanks again!
  • pete.whelan
    pete.whelan Posts: 788
    I put a new thread on my sons bike (105) when he managed to strip the thread. I now have the tools and the thread inserts.
    It's not a difficult job.
    I could do it for you (for the cost of parts)
    Recipe: shave legs sparingly, rub in embrocation and drizzle with freshly squeezed baby oil.
  • cycleclinic
    cycleclinic Posts: 6,865
    Post it to me I am always getting cranks to repair. I have the kit to install a bush to replace the damaged thread.

    or post to pete by the looks of it.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • Thanks you very much guys, that would be perfect! I've just had another look and the thread is pretty much stripped clean - is this a big deal or would it still be repairable? What sort of cost would it be to get done?
  • pete.whelan
    pete.whelan Posts: 788
    you have PM
    Recipe: shave legs sparingly, rub in embrocation and drizzle with freshly squeezed baby oil.
  • david37
    david37 Posts: 1,313
    I can repair it for you, postage plus a tenner.
  • photonic69
    photonic69 Posts: 2,962
    I think he might have sorted it by now!


    Sometimes. Maybe. Possibly.

  • david37
    david37 Posts: 1,313

    I think he might have sorted it by now!

    d'oh :)