I have a Square taper BB on 2 of my bikes. Tried getting the cranks off with the puller, but after a couple revolutions it comes to a stop and can't be budged, even after hitting it with a hammer. (YES, I know I shouldn't do that, but it wouldn't budge.) This happens on both bikes. Does this sound like something I'm doing wrong? (I did it the way I saw on a video.) Could it be the puller not working properly? Or, a problem with the cranks/BB? Any other way of getting them off (without destroying the cranks, BB, or frame)?

1. Make sure that the threads are clean and lightly greased, that the puller is screwed all the way in - back off the center "pusher" so it doesn't interfere with screwing the outer puller all the way in - you want all of the crank threads engaged to minimize the risk of stripping them
2. Make sure that there are no washers of other bits in the hole, and that the pusher directly contacts the end of the BB spindle.
3. I always do these sorts of jobs with the bike on the ground and the wheels on - no torque I can exert with a crank puller will exceed the torque I can exert with my legs - torque that the bike was designed to accommodate
4. No hammer - if you need more torque, use some sort of extension or cheater bar - never a hammer
5. Personally I prefer the "cylindrical" type puller with a hex end that requires a ratchet or other wrench, as opposed to the Park-type with the built-in handle - the former allows you to set the lever at any angle to exert the best effort - like horizontally so you can use body weight.
6. Assuming that the puller is correctly installed, and the crank is genuinely jammed on the taper, you might try laying the bike on its side and filling the crank cavity with penetrating oil overnight. I've never had to resort to this, but it might work.
7. Try pulling there other crank arm and extracting the BB from that side - being able to address the stuck crank mounted on a vise might give you more options

Thanks for the info. Just managed to get it off. After watching another video, I realized the problem: at the end of the puller there is some kind of cap (that is the same width as the threads), which prevented the smaller part inside from getting inside the square part. Still had to tap it with the hammer to get it started, but this time it moved with each hit.

Just curious, what style of crank puller are you using? I have a couple — one is a the Park CCP-22 that has the handle attached to the inner threaded pulling mechanism. The other is similar to the Park CWP-7 (but isn’t actually a Park tool) which DOESN’T have a handle attached to it, and requires use of an open end wrench to turn the inner mechanism. On this one, both the outer part threaded into the cranks AND the inner part turned to force the crank off the spindle have an external hex fitting for using a wrench. On more than one occasion, I have found myself not paying attention, and cranking down on the outer part wondering why the damn crank won’t come off…then feeling lucky that I didn’t just strip the threads from the crank. I mean it’s a boneheaded move on my part, and you’re probably (hopefully) not doing this. — Dan

Its a Park, with a small black handle.

That Puller is NOT for Square Taper Cranks!

it's for Octa-link and ISIS style cranks!

STOP NOW, before you Damage something.

oops.. too late...
good luck...
depending on the exact style of threads your BB spindle uses, you may have just ruined it.
the snap ring that holds the pad on may be damaged too.

At our bike Co-op we go through one of the black-handled Park crankarm pullers every week. The (unsupervised) user will first try to apply full body weight to torque the crankarm off, and when the nose of the tool bottoms-out, will often resort to a 2' long cheater bar to escalate. Last time I checked we had a sorry row of mangled pullers that needed replacement.

Ditto situation for 15mm Park cone wrenches. We go through one per week due to users applying these to torque end nuts on hubs. They are great tools, but education is sorely required - shall we say.

This is (one of) my puller(s):



It's the old version Park, but the important bit is up at the hole end.
It's a flanged sheet-matal screw held on with a badly-fitting wingnut, that has had the flange squared to fit inside the square hole in a crankarm.
That goes in the end of the axle, and the puller pushes on it, not directly on the axle.
This makes sure hat the nose of the puller does not hit the edges of the crank - and the extra degree of freedom in the torque chain makes the nose less likely to gall.

WOW, One a week. That has got to be a record. Some people shouldn't be allowed to touch tools without a ton of training.

That cap is an adaptor for Octalink splined cranks - remove it to use with square tapers. If not removable you need a different puller.

If all else fails on a metal crank arm try heating it with an electric heat gun. Don't get it red hot.

explain how heat will remedy someone using the wrong puller.

I don't see the original post saying that they were using the wrong puller. Admittedly I didn't read every post in the tread.

It was too much to read to post 3 when the OP explained how they were using the tool wrong?

That's a good suggestion if the problem is really just a tight crank.

Beat me to it (assuming correct tool to remove). Aluminum has a high coefficient of thermal expansion versus steel, and will expand to loosen the press fit at the taper. However, aluminum can lose its strength at a fairly low temp, and hot air transfers heat slower than water. Thus, I recommend boiling a small pot of water, and pour it over the crank at the tapers, or even better, turn the bike with that crank down and submerged in the pot, as it being aluminum, the heat will rapidly transfer away from the spindle end, but not if you submerge the whole crank arm for time enough to get it close to boiling water temp, which is still a safe temp for aluminum. This all assumes you are at less than a couple thousand feet above sea level, so the boiling temp is not reduced a lot.

Heat, applied with a soldering iron to a bolt, or heat gun for something like a bottom bracket, is also ideal for softening anaerobic thread locking adhesive ("Loctite"), for much easier disassembly.

Or, as some of the more experienced mechanics here have pointed out repeatedly in earlier threads, you can remove the crank bolt and washer and bring them along while you ride the bike until the crank begins to work its way loose. Reinstall and snug up the bolt and washer, and you'll have no trouble pulling the crank when you get home.

Who would ever think it's a good idea to use Loctite on crank bolts?

True but seen this a few times when someone has a crank bolt that keeps coming loose because they don't torque it on properly and just douse it in Loctite (or JB Weld ) as a solution.

If the crank is pressed on totally dry and a heavy press, it may not loosen from riding alone. But I'll grant you, I hadn't thought of that when first mechanicing in my youth.

I didn't mean my comment as Loctite on crank spindle bolts, just as a general reference to heat as an aid in loosening things. However, I have seen chainring bolts Loctited (blue) from the factory. I've seen so many instances of snapped small screws that had been Loctited (usually with red), the person totally unaware that a little heat would have prevented that. Loctite (and other threadlocker) website lists softening temp for each type.

As long as you use Green or Blue, what's the problem?
If nothing else, you have some corrosion protection, although other things like grease or anti-seize do also.
No corrosion would make the crank bolt less likely to be seized.

Someone who had a crank bolt fall out and lost it on the road? Does that happen? They might think a loose crank happened because the screw loosened, rather than a failure to torque it correctly in the first place.

I have had a couple of stuck square taper crank arms. Know the first thing I do is spray some Kriol penetrating oil into the taper and let tit sit overnight. I have also warmed the aluminum crank with a hair dryer. Does not always work. Once as a last resort I used a flywheel puller. Scary but I was surprised it did not damage the crank arm. No issues after using the Kriol. But then the Kriol may prevent galling causing the parts to stick together.

25 years ago or something, I bought the Octalink specific crank puller. At the time, that's what I had on my bikes. At some point, I pulled the little disc off and used it as a regular puller for square taper. It's worked fine for both for all that time.

I did lose the little part that makes it work for Octalink. Like decades ago. I used a flanged nut, not sure of the size, but wide enough to contact the bottom bracket but narrow enough that it doesn't contact the crank. I hold it in place with an m5 bolt.

It works perfectly.

Pennies, dimes, and washers tend to never be the right size and get deformed when used this way.

Done this as well. Also just dropping a 5mm 1/4" socket in the hole works as well for square taper. This should really get the gottausethecorrecttool guys going LOL

This is good advice. I’ve had to pull cranks a couple of times since I read this a few weeks ago. I’m surprised by how much the head of the screw gets marred by the crank puller. It saves that from happening to the end of the spindle.

Dan