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    crank arm removal

    The crank arm is not coming off. I stripped the threads with the conventional square taper crank arm removal tool. It's on there very, very tight.

    I am using a three arm puller and have had it on for days under tension, adding PB blaster to the joint and adding heat with a heat gun to the outside of the crank arm. I don't trust adding and more tension to the puller. It's as tight as it feels like it can go and the arms don't have a large surface to grip. I've tried tapping the crank with a hammer and tapping the end of the puller lightly to jar it loose.

    Any ideas?

    It isn't budging.

    by cfpbeck

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    26 Comments

    3. Andy202007 on

      Are you sure that the crank puller hasn’t forced its way to the bottom of the hole? (I can’t quite tell from the photos.)

    6. Unicycleterrorist on

      Hose it with penetrating oil, wait a bit, tighten puller again, wiggle on the crank arm with your hand. If that doesn’t make it budge, cut diagonally across with an angle grinder and it’ll slip right off…you’ll probably damage the shank of the BB, be careful with your frame though lol

    7. justburningaccount on

      Just ride it round without the bolt in

      The cranks shot anyway if the threads are gone

    8. Mick_Limerick on

      Ride it around the neighborhood with the bolt out of it, give it some curb drops and bounce on it. It’ll likely work itself off in 15 minutes

    9. spleeble on

      You have to be kidding. I find it really hard to believe that a square taper crank is too seized for that puller. 

      My first guess is that the puller is hanging up on the crank itself somewhere. You might have a bigger target if you you put the bolt in lightly and press against the head. 

      If it’s really actually seized then I would try in order: 

      1) pedaling hard up a hill with the crank bolts out (destroys the crank)

      2) remove the other crank arm and the bottom bracket cups (looks like you’d have access) and remove all of it (destroys both) 

      3) cut the crank around the hole in a couple places (destroys the crank and maybe the bb)

      4) cut the spindle (destroys both, plus the frame if you mess up)

    11. blp9 on

      I think photo #3 is the smoking gun — that crank isn’t square to the spindle, which means *something* is wrong.

      I agree with other posters who are suggesting you might not be getting traction between the gear puller and the actual spindle (like you’re hitting the crank not the spindle) — back it off and see if you see tool marks on the inside of the crank.

    12. BadPenguin007 on

      Ypu know they make a tool for that right? A crank-arm puller? Hope your Brooks saddle is A-OK.

    13. DirkChungus on

      Frame upside down, blow torch the crank arm (try not to get the frame too hot) then batter it with a lump hammer. Failing that angle grinder through the BB axle, looks like you have plenty of space.

    15. YeaYouGoWriteAReview on

      Keep cranking on the puller and beat the crank arm to death. Eventually it will detonate and you’ll have to check yourself for shrapnel wounds, but after 24 hours your heart rate will return to normal.

      After that it’s just the occasional nightmare about your bike eating your face off, but that’s only once a month for 3 or 4 years.

    16. EntropicByDesignEC on

      I don’t see a heat gun putting enough heat into this to do much of anything. I’m not knowledgeable with bikes, but I am with this sort of thing in a general sense. Been in the mechanical and fabrication space most of my life.

      If the more knowledgeable folks here, who know this issue more specifically, don’t give you a better route to getting this off, go to Walmart and buy a cheap propane torches and small tank. Or failing that, find a local auto shop, not a corporate place, but some locally owned hole in the wall, ask them if you can use their torch for a few bucks, show them the bike. More than likely, they won’t even charge you. Best case they see it as a challenge and all glom in to help you out..they’ll have air tools and such as well.

      Just my .02. again, folks more knowledgeable about bikes in general may have a much better solution

    17. Mindless_Stage7116 on

      Has no one noticed that this is an eccentric BB and will likely come out of the frame very easily. Then, you can move the project to a bench vise. Also, the correct bicycle specific puller would be the best option. A few suppliers offer an oversized square taper puller for this problem.

    18. dogged_jon on

      Try hitting harder on the puller bolt while it’s pulled up tight. Probably warm the crank first.

    19. UpbeatSmoke4209 on

      I’ve tried in the past to do the same thing your doing with a bearing puller it never worked you need to just get the park tool crank puller it makes easy work out of it

    20. Somasaga58 on

      I have used a pickle fork successfully but I had to beat on it with a small sledge. I have also just ridden the bike around the neighborhood but that took a long time.

    21. step1makeart on

      The crank arm is headed for metal recycling, so you might as well get destructive (once you confirm the threaded central leg isn’t just pushing on a lip of the crank arm): cut a slit in the arm with a Dremel, roughly where the right arm of your puller is in the first picture. 

    22. alex_evo on

      Hit the end of the puller with a hammer towards the crank then turn with a spanner till it locks up and repeat the process, works for bearings never tried for cranks…!

    25. AMTK207 on

      Square taper’s Achilles’ heel.  

      Please advise what worked when it finally comes apart.  

    26. DrunkMoses on

      I had this same thing happen a few weeks ago. I was not planning to re-use the cranks or the BB, so I resorted to the tool that is notorious for making any problem you have, even worse. A dremel because I had one on hand and didn’t feel like ordering a bearing puller or taking the trip of shame to the bike shop.

      (5) or so cutting blades later, some near misses with cutting discs flying past my head, and several hours of making a mess of things I did get that crank off. It was honestly miserable (I had to make many many cuts before I was able to get an angle that I could get the cutting wheel all the way through to the spindle), but I was somewhat pleased with myself when the job was done and I had managed not to knacker anything else up. Would not recommend this method for the faint of heart. If you have access to a proper grinder on the other hand, this would be a 30 second job…

      Edit: I had to cut through the drive side, which meant more material. It would be a lot simpler if the only side you’ve stripped is the non drive side crank.

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