I have an old (70s?) Motobecane Mirage that I'm using as a project bike, and trying to remove the cranks, which are the "square taper" kind (they're labeled "Tourney"). I bought a Park Tool CWP-7 crank puller, but I can't seem to screw it onto the threads of the crank by more than 1/4 turn or so. I measured the interior diameter of the socket on the crank to be about 20.7 mm, which I think is about right for a 22mm tool, is that right? Do I need a different size tool, or is the problem the thread pitch?

thanks!!

try turning the tool anti clockwise a little bit till you feel you're right to thread it on properly clockwise

otherwise it could be the threads are stripped on the crank

you'd think that'd go without saying, but i have forgotten to unscrew the bolt out of the tool first sometimes, and i've removed plenty

make sure you've unscrewed the crank lock nut, step one :-)

BTW, my park tool seems to thread on all old and newer bike cranks, only problem i had is if the threads on the cranks are stripped
then, you'd have to cut it off, steel cutter

Is it a Stronglight crank - they used different threads.Whoops - yes, he said Tourney. Sometimes the 1st few thread get damaged - we used to have a tool in the shop meant to clear them.

And remove any washers, if present.

No, if it's a Tourney crank, it will use a standard 22mm extractor:

When the typical crank extractor fails, the next step is a "gear puller". Google that exact phrase "Gear puller" and get one. They kinda look like a spider and they are not expensive.

I have had better luck with Jacobs chuck wedges.

i got one of those lying around and tried that before i bought a crank tool, if you can get a good grip they seem to bend the chain rings

A Tourney crankset could also be Takagi (before Shimano acquired them), but still standard threads.

Yes….the outer thread will go in further if you back out the inner one first; but it doesn’t have to be that tight. The inner thread does all the work.

Same here.

Spoken with no understanding of action and reaction For the inner part/driver push enough against the axle it must be held by the same force in place, in the crank arm threads. So 10lbs of extracting force is needed it is born by the outer sleeve as well as the inner driver. Anything else and the driver wouldn't be able to push those 10 lbs of force, the driver would just push it's self away from the arm (which is what happens when a crank arm's extractor threads pull out/strip out). Andy (who stripped out an am today, ask and I'll tell).

Do you have any experience with the Stein crank extractor which consists of a self tapping crank extractor tool? I think Stein is a great American. Not as great as John McCain, but then, has John McCain ever saved a crank arm with stripped threads?

I have one of those, and it works great. Agree with your assessment of the man too. If you call his contact number, he actually answers the phone in person,and is very pleasant and helpful. I have a number of his tools and would recommend them.
The crank extractor is not exactly as you describe though. It is a system that consists of a piloted oversize tap and a separate extractor tool or self extractor caps.

I have no personal experience with the Stein extractor but have also heard of good results from friends also in the LBS business. I do have and used other Stein products and agree with their functionality. Also agree that it's refreshing to see a person who lets his creations speak for themselves, in today's over hyped social media world this is an uncommon position to take. Andy

Wow, thanks for all the input! I took my bike to a local bike repair co-op and we were able to get the cranks off with a standard tool. It turns out I was being too careful of stripping the crank threads, and just needed to apply more force. Also I think the fact that the crank has a slight curve to it threw me off; I was trying to hold it perpendicular to the crank, but that wasn't quite parallel to the spindle.