boogman

I've attempted to remove the crank on two separate bikes, both with square tapered bottom bracket.. I used the crank extractor and then turned the thing with as much power as I had and it simply wouldn't budge..

The attempt on the second bike ended up stripping the thread from within the crank arm's pivot hole.

I'm now afraid to attempt the same thing on my Pugsley complete. However that bike has an external bottom bracket.. I'm hoping the procedure on that design would be simpler...

bobotech

You ARE removing the nut/bolt from inside the crank arm mounting point first, right? And then you are checking to make sure there isn't a washer in there too, right?

boogman

Yep, removed the bolt first, then all I see inside is a square opening..Beyond the opening, I assume is the BB spindle surface. I have never seen or looked for a washer after removing the bolt.. is the washer lodged inside the crank pivot hole? Or would it be pretty obvious that it's there?

On my crank extractor, I removed the larger tip from the extractor leaving only the smaller diameter head, which fits within the square opening.. Screwed in the extractor and started torquing it with a wrench... Does that sound about right?

bobotech

As for the washer, it would be obvious if you looked into the hole where the square taper is located. If there was one in there, you would see it. If you don't see it, then there isn't one.

When I engage the extractor, the part that actually screws into the threads on the crank arm, I will screw it in fully and then use a wrench to tighten it down to make sure I have plenty of engagement. Then I will insert the handle portion and crank away.

weshigh

Are you screwing the crank puller into the crank arm or into the bottom bracket opening? The crank puller should screw into the crank arm and then push against BB thus pulling itself off the BB. Your sentense makes it sound like you are screwing the crank puller into the bottom bracket.

Chombi

Still could be a washers in the crank bolt wells. Double check and Look very carefully. Many tend to miss the washer as it is sometimes bright silver in color from getting scraped up by the crankset bolt when it is tightened so that it blends in with the aluminum crankset material around it.

Chombi

3alarmer 

Your description of what you're doing sounds reasonably correct.

1. a properly inserted crank puller of the correct threading and diameter
should never strip a crank's threads unless it's not been inserted deeply
enough (sometimes you have to wrench it in all the way) or there's an
obstruction......most commonly the washer that's been left by mistake.

2. If a square taper crank has been on the spindle for a long time, it
can be on there pretty tight......PB Blaster from the back and at the
end of the spindle helps......i use it routinely.

3. What is the length of the lever arm on the wrench you're using
to turn the puller ?? Also, are you certain you backed the internal
part of the puller all the way out prior to screwing in the external part ?

If your wrench is short, and you're sure the puller is in deep, and there
are no washers or other obstructions, get a longer handled wrench.

funky_snowman

What type of crank extractor are you using? I just had this issue once because I was a bone-head and was using the wrong type of extractor. Make sure the end of the extractor is actually pushing against the spindle, and not against the crank arm itself. If it's just stripped out, whack it a few times with a rubber mallet.

ultraman6970

Looks like you need to use the old piece of Wood and hammer technique. very effective

onespeedbiker

Assuming you did not leave the washer inside and you are using the correct head on the tool, pulling the threads out of a crank is usually the result of someone not screwing the crank removal tool far enough (ie all the way); it was either you are someone before you. As far as not getting the crank to come off after maximum effort (assuming the same as above), that is usually the result of using the tool with with a 6" handle. After years of bending over bicycles, pushing and pulling on that dinky handle. I bought a compact crank tool like below. With one of these you can use any size adjustable wrench you want; I find a 12" takes care of most crank extractions..

DannoXYZ 

As mentioned, make sure there's no washer in the crankarm.

When using any extractor too, such as the one posted above, it's a good idea to disassemble the tool into two separate pieces. Verify that the inner pusher-part clears the crankarm square-taper completely and can push only on the end of the BB spindle.

Then screw the outer sleeve part that goes into the crankarm in all the way. Use an adjustable-wrench to snug it down, 10-15 lb*ft should do. This makes sure that the maximum number of threads are engaged in the crankarm and also prevents any wiggling that can strip out the threads.

Finally, screw in the inner pusher part. When it contacts the spindle, use TWO wrenches on the tool. One to hold the outer sleeve part steady while you crank down on the inner pusher part. This prevents additional torque on the crankarm threads that can strip them out. Best to position the wrenches so they are about 30-45 degrees apart and squeeze them together. Or 30-45 degrees apart in the other direction and pull them apart.

DieselDan

Having had to rebuild about 600 bottom brackets last winter, I had a few crankarms that were "stuck" to the spindle and would not come off, with the result of the threads coming out with the pulling tool

The fix was a bit destructive and not recommended if you plan to reuse that crankarm. I am dealing with somewhat cheap fleet rentals. The work is located near the ocean.

rsacilotto

+1 an ISIS/Octalink crank puller will not work with a square-taper crank.

onespeedbiker

OTOH the OP is now going to R&R an external BB, which is certainly easier and more user friendly..

Kimmo

I dig the external BB format. I wish Shimano would do a loose ball version... that'd be way cool.

They need a sexier way to attach the left crank, too. Can't see Campy's Hirth joint sitting too well with adjustable preload, though : /


...Hey. Here's a thought - what does a Hollowtech tandem crankset look like? Maybe you could use two Campy rights, but Shimano would definitely need something specific to cover that.

boogman

Hey thanks for all the replies..

Yes - When I screwed the crank extractor into the crank, I did not screw it in all the way. On the initial attempt, I hand tightened it only. The crank would not budge upon torquing the extractor.. Then on the subsequent install of the extractor, I torqued down the extractor with my wrench when installing it. It was during that process that the threads were stripped off. I assume my initial attempt is when the damage was done.

I am using an extractor where the tip is changeable.. I removed the button-looking tip and what remained seemed to clear the square taper. I thought my extractor only had a removal button tip, but it seems like the movable sleeve on the tip is also removable(like the one below), but I never removed it...



Arghh.. so just to confirm.. the external BB style on my pugsley complete bike is much easier to remove the crank? I won't have to deal with using the extractor on that bike?

Kimmo

Yeah, that's right - two-piece cranks come apart with an allen key.