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  1. #1
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    Stuck/Seized Crank Bolt - Pro Tips? (pic)

    [SOLVED refer post #12]

    Hey Guys

    I picked up a complete 2nd hand bike on TradeMe (like eBay in NZ) and am currently going through the dismantling process. As you can imagine I've hit a couple of snags - I'll keep each problem (2 atm) to a separate thread.

    Problem #2
    The drive-side crank bolt is seized on like a ........

    The other side came off easily (as did the crank with a crank puller and even the bottom bracket part on that side) but I cannot get this bolt off for the life of me. I have a chain whip and a big bad spanner which gives me good leverage but no budgey.

    Is this type of crank bolt DEFINITELY CCW (I've tried both ways...)?
    Any Pro Tips for removing this thing outside of taking to the LBS? I've tried liberal amounts of WD40 from front and back and still nothing. It appears to be on there good.

    Sorry I know there are other threads on this topic but I have read all of Google and still can't get this off (haven't tried everything as I don't have a blowtorch/angle grinder!!!!!).
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    Last edited by sproyd; 01-31-12 at 05:38 PM.

  2. #2
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    remove pedals, slip pipe over crank arm. use a long ratchet and 14mm socket or pipe the ratchet too

  3. #3
    Senior Member Bill Kapaun's Avatar
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    Get REAL penetrating oil.
    Lay bike on side with the crank side up and fill cavity with PO.
    Let soak for a while. Repeat and let soak a couple hours.
    While soaking, give bolt head some light taps like you are trying to make it "ring". Speed, not force here. That helps the oil to "wick in" to the tiny places.

    Then Get the BIG tools out.

  4. #4
    Senior Member IthaDan's Avatar
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    you might be able to hammer on a 12 point socket one size smaller than the crank bolt (14mm?). If not, google up "bolt extractor" and find one in NZ.

    FYI- Bolt extractors look like this-



    Also: if you're scrapping the crank/bb, you might be able to get a thin pair of vicegrips on the BB and thread that out. Remember, it's most likely reverse threaded. (the BB cartridge is reverse, the crank bolt is normal- righty tighty, lefty loosey.)
    Last edited by IthaDan; 01-30-12 at 09:40 PM. Reason: vicegrips!

  5. #5
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    Quote Originally Posted by reptilezs View Post
    remove pedals, slip pipe over crank arm. use a long ratchet and 14mm socket or pipe the ratchet too
    Pedal also seized into the crank arm.... can't get it off.

  6. #6
    Senior Member Bill Kapaun's Avatar
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    Get REAL penetrating oil......

  7. #7
    Senior Member commo_soulja's Avatar
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    Quote Originally Posted by Bill Kapaun View Post
    Get REAL penetrating oil......
    PB Blaster works really well.
    Mythical Creatures Touched Me in my Bathing Suit Area.

  8. #8
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    Quote Originally Posted by sproyd View Post
    Pedal also seized into the crank arm.... can't get it off.
    toe strap crank arm to frame

  9. #9
    Senior Member curbtender's Avatar
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    If you have someone to help, get a socket and a breaker bar and have them tap it while you turn.

  10. #10
    Lover of Old Chrome Moly Myosmith's Avatar
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    Get some Liquid Wrench, Marvel Mystery Oil or other real penetrating oil and let it wick into the threads from every angle a couple times a day for a few days. I've had the best luck with stuck pedals by placing some form of bar through the rear triangle to keep the opposite pedal from rotating, then getting a wrench on the offending pedal so that it forms a narrow an angle as possible with the crank. Apply force to the wrench with one hand while tapping it hard with a hammer in the other.

    As mentioned above, a 3/8 or 1/2" drive breaker bar will give you all the torque you need for the crank bolt, but it is possible to snap the bolt head off so penetrating oil is your best bet. It's hard to use heat on a crank bolt because the crank protects the spindle, which is where the heat would ideally be applied. You could try heating the bolt head and then allowing it to cool in hopes that the difference in rates of expansion and contraction between it and the spindle will loosen things up, but heating the bolt will actually expand it making it tighter in the threads until it cools off again. If you know someone with an impact wrench or impact drill that will take a socket adapter, the hammering vibration can often loosen stubborn bolts.
    Lead, follow or get out of the way

  11. #11
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    If all else fails and you are willing to sacrifice the crank, you can use a hacksaw to cut the crankarm apart, then hacksaw off the bolt, then remove the BB, then replace crank and BB.

    A crank and BB of similar quality will likely cost ~$35 or so.

    It is very uncommon that a crank bolt cannot be removed with a long wrench and a strong arm. As mentioned above, put a 'cheater bar' on the crank arm and on the wrench and it should come off. If it doesn't, perhaps the original owner used some sort of threadlocker.

    Chain whips are not often used on cranks as the crank arm usually has as much leverage.

  12. #12
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    Winning!!

    Ladies and Gents problem finally, unbelievably (to me anyway) solved.

    The key here (as many of you pointed out) was leverage. Now I didn't have the right extensions etc for my socket wrench - went and bought an adaptor that I thought would help but it ended up being a waste of $12.50.

    Anyway, my crank extractor tool features a 14mm socket with a hex on the outside for a spanner. I had tried this before but to no avail.

    1) I left the bolt to soak in WD40 (yes I know, not a reAL penetrating oil but it was to hand) for about 3 or so hours.

    2) I tied the pedal to the frame with rope (similar to as reptilezs suggested with the toe straps) so it wouldn't budge.

    3) I then put the crank extractor tool over the bolt head, attached a monkey wrench, and used the now removed fork over the wrench for extreme leverage.

    4) It popped right off and came loose easily after that. The cranks and bottom bracket both came out without an issue (probably in part to the 2,000L of WD40 that had sprayed their way!!)

    A pic attached showing the leverage chain for punter's reference - no pics of me actually doing it sorry.


    Thanks all - all bike problems solved (for the time being). Now to paint strip the frame... wish me luck
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