How do I remove my Crankset with a Hacksaw?

Discussion in 'Cycling Equipment' started by xxtimber, Aug 12, 2010.

  1. xxtimber

    xxtimber New Member

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    I have a bare frame with only a truvativ crankset square taper that is stuck. I used a crank extracter and banged with with a rubber mallet but couldn't remove it. I don't need to keep the crankset.

    How do I remove my Crankset with a Hacksaw?
    Where am I supposed to cut?
     
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  2. swampy1970

    swampy1970 Well-Known Member

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    Did the extractor strip out the threads inside the crank?

    Did you make sure that after removing the bolt that you removed the washer too and are you sure that you're using the correct extractor?

    Just want to double check that you know how to properly use those fine little tools.

    Could you video tape your attempts at cutting a crank off with a hacksaw? I could do with a laugh. I expect things may get comical rather quickly... Sorry, couldn't resist.

    Do you need to keep the bottom bracket?
     
  3. davereo

    davereo Well-Known Member

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    If you are not planning on saving any of the componets and just need the frame try applying some heat with a propane torch to the crank while it is under pressure of the extractor. Lightly tap the extractor to try and shock it off.
    As Swampy has suggested a video would be great. Seeing as you now will be adding a torch to the hacksaw for greater visual effect.
     
  4. xxtimber

    xxtimber New Member

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    Yup I do know how to use an extracter. I was told by the bike shop owner that this is common with the Truvativ crankset and the park tools extracter is newer than the crankset resulting in a slighgt size difference. What I did was compress the aluminum making the crank tighter.

    I don't need to keep the BB.

    Is there something majorly wrong with using a hacksaw? What's so funny?::eek:

    I'm not sure where to cut.

    And I dont have a propane torch. I'm just looking for some advice as to where to saw...or is there something majorly wrong with this?
     
  5. 531Aussie

    531Aussie Well-Known Member

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    Yep, as they say, perhaps check one more time that the extractor will work. Sometimes ya think that the extractor is screwed right in went it's not. Makes sure that the 'pusher' bit isn't preventing you getting the extractor screwed all the way in. Sometimes the pusher bit looks likes in undone enough when it's not.

    Do you need the bottom bracket? If not, I'd consider sawing the axle, but is it possible to hacksaw a steel square axle? I've never tried. :) Either way, it would be tricky to get a saw in there, even with the chainrings taken off. I suppose you could saw off the crank splines then try to get at the axle.

    Another possible option is slipping a pickle fork behind the crank and whacking it with a mallet, but only if the bottom bracket is protruding and 'protecting' the frame from the pressure of the tool -- and if you're not fussed about dinting the bottom bracket -- otherwise, don't do it. I once got a crank off this way.

    [​IMG]
     
  6. swampy1970

    swampy1970 Well-Known Member

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    As 531Aussie said with his tool - your forked! :p

    Heat would be quickest. $20 at home depot for a torch - they do a couple of different ones based on heat requirements. Heat the inside of the crank where the crank bolt used to go - it'll help protect the frame from accidental paint melting.

    You could wrestle it off... take the pedals off, lay it on the floor, stand on one crank and yank on the other.

    If I had to self destruct a crank I'd drill the ba$tard off. Get a couple of sizes of cobalt drills and drill out the bottom bracket - the thing has a big hole in it already. It's probably made from a fairly tough steel but nothing a good drill couldn't get through in short order. You may not need to drill that far either - the vibration and heat will help.

    IF you're lazy, a local machine shop will have these off for you in this manner in about 5 minutes and the cost wont be that much.

    Saftey glasses (oakleys conveniently are ANSI Z91 rated ;) ) and gloves recommended. You'll probably want to use a corded drill for this aka a BFD (big [email protected] drill)

    A Milwaukee sawzall... Now that'd be a good video. You could probably have the crank off in about 15 seconds with that... Cut a diagonal line across the top edge of the crank (the part that's furthest up if the pedal is down). This is how I'd cut it with a good hacksaw blade that's designed for soft metals. Spend $5 and get the right blade.

    A piece of gaffa (or ducttape) will help stop initial blade slippage - stick a piece on and cut.

    Or - you could use a center punch to make a line of holes around the top edge of the crank (if the pedal is down then you'll do this on the top of the crank). Use a 4mm drill or similar to drill through the crank and then drill those holes out with something bigger so that the holes meet and the crank falls off. Aluminum is soft... this shouldn't take long.

    For added effect, skip the second round of drilling and get a BFCC (big f^&king cold chisel) and the mythical BFH to smack the snot out of the top of the crank. If you have the drilled holes fairly close together it'll go. Definitely a saftey glasses and gloves moment. I'd keep pets and small children away from the area too... unless you don't particularly care for the neighbors dog.

    If you need to ask what a BFH is, hand your "man card" in at the door. Panties and aprons are available in the metrosexual isle.

    Or you could drill some holes and get some blasting caps and just fragment the entire crank. Video is non-optional.
     
  7. xxtimber

    xxtimber New Member

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    Thank you for this! Great advice. I will get started soon:D
     
  8. KD5NRH

    KD5NRH New Member

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    Heck, be lazy; heat it up and let it cool a few times and see if it just falls off from the temperature cycling. After three or four runs of that, if it hasn't come off already, then try the extractor again.
     
  9. alienator

    alienator Well-Known Member

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    Go high tech and use a big ass laser.
     
  10. dhk2

    dhk2 Active Member

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    swampy, your thread has some great info on the use of the BFH and other proper tools. It's obvious you understand the creative and fun part of bike maintenance starts only after the fateful decision to ruin stuff :)

    I'd probably use the drill to make holes in the end of the crankarm, in line with the spindle. Since the arm is "stretched" over the axle, bet it would crack through and fall off with just a few small holes. Of course, if still needed, a blow from your favorite BFCC/BFH could split open the crack.
     
  11. KD5NRH

    KD5NRH New Member

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    Ass laser? Isn't that the special power that Superman never told anybody about?
     
  12. garage sale GT

    garage sale GT New Member

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    Don't use a pickle fork or any kind of hammer. Sacrifice the bottom bracket for the safety of the frame and slice through the spindles (i.e. slice through the crank axle just inside the crank arms), then remove the bb. You'll need a new bb as well as crank arms but you'll save the frame from damage.

    I suppose if you wanted to try and save the BB you could reverse the blade in the hacksaw so the teeth pointed the other way, and try laying the blade along the spindle and sawing the crank arm outward, but you'd probably have to do it on at least two sides before it came off.
     
  13. jhuskey

    jhuskey Moderator

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    Nobody has recommended a drill press with a 2 inch bit, can't believe it.
    Heat usually works, agree.
     
  14. Bike4Him

    Bike4Him New Member

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    What frame are you saving?
    Vintage, classic, timeless, etc?
     
  15. billydonn

    billydonn New Member

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    I would be trying the heat method first... making sure you work outside and don't burn the house down. The sawzall method seems reasonable provided you get a good blade and work very carefully. DeWalt or Bosch will work as well as Milwaukee.:cool: Methods involving shock to the frame/BB assembly via use of BFH and chisels or pickelforks would be a very last resort as there is too much risk of bending the frame.
     
  16. alienator

    alienator Well-Known Member

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    Just snip the cranks off with this:

    [​IMG]
     
  17. Yojimbo_

    Yojimbo_ Well-Known Member

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    Why not take it into a shop and let them worry about it? I'll bet they've got tons more experience at these things than you do.
     
  18. nicesmokes

    nicesmokes New Member

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    Yes - very old post - but the answer is: rock hammer and screwdriver, followed by oil, followed by acetylene torch, followed by drill (three holes then diagonal drill to connect), followed by manual hacksaw, more hammering, more sawing through, then large screwdriver acting as wedge in hacksaw channel, followed by several blows. Very simple. Or.... don't by cheap-a55 Chinese crank extractor tool that strips the threads on the crank in the first place. I may post video for your amusement.
     
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