I found a discarded Schwinn World Sport and am disassembling it for parts. The crank arms (if that's the right word for the shafts that connect the pedals to the bottom bracket) are Sugino aluminum. I removed a cap from each side (just a screwdriver slot) and a nut (7/16" socket worked fine), but can't go farther. Each arm fits onto a square shaft. Moderate use of a hammer on the back side didn't do it, and I can't get my automotive gear puller to stay centered on the shaft.

Am I missing something obvious? I've read about "crank pullers" in other threads, but don't have one. I know this was a cheap bike to begin with, but I'd rather not damage anything unnecessarily. Any suggestions?

Theres a couple ways you can do it without a crank puller. One is to take a hammer and a drive and put the bike on the edge of a bench where the frame near the bb is being supported and tap at the inside of the crankarm from the opposide direction pushing it off the spindle.
Also you can get a prybar and edge it in there between the crankarm and bb and leverage away

You need a crank pulling tool.

Thanks very much, Rick and San. I'm obviously a novice at bicycle mechanics, but have been an antique car hobbyist for many years... and just removed the crank arms using a tie-rod "pickle fork," applied with a little vigor between each arm and the bottom bracket. Each of them popped right off with no apparent damage.

Again, I appreciate your advice!

You should still consider investing in a crank puller. They're around $10 at a shop (but can be found for less) and will work for just about any bike with that style of thread.

+1
A dedicated crank puller removes the crank with the least possibility of damage or wear. I don't know what your "pickle fork" tool is, but if it applies any uneven action, it will possibly cause the softer crank to wear, not necessarily visibly. With repeated use you might end up with a "wobbly" chainring rotation.

Then you were lucky. If the crankarms were actually installed with proper torque then you would've risked damaging the frame, bb or crank while doing this removal. A crank puller is $10. Go buy it. Seriously.

You could also ride around the block with the securing bolts off. The cranks are bound to loosen when riding.

Yes, they will. And after that you can discard the crank since the square taper hole will no longer be square.

All taper holes deteriorate over time no matter what you do. All of my cranks have been loose at one time or another and, after many years, I still have to bottom out one. Even if I did, the alu hole could be restored, good for a number of extra years, by a judicious use of a chisel.

Yeah, this way you can sure it's irreperably damaged with your method. No guess work needed.

Pickle fork or ball joint/tie rod separator:

It's a tool that I've never found any good use for as the proper puller always seems to work better and without any risk of damage to the parts being separated. Also, it's guaranteed to cause damage attempting to remove an aluminum crank arm with one.

How hard do you ride the bikes that you've "repaired" square taper holes in the cranks with a chisel? Using proper torque in the first place, a decent square taper crank should outlast you before the hole has deteriorated to the point where it won't stay tight.

You use that tool when

a) Cranks are seized on
b) Crank arm removal threads are strippped
c) a) or b) with customer replacing cranks anyways.

I think this tool would work much better in any of those situations:

Good one is the Posi-Lock puller:



$50 at Sears

Get one. I have a Park Tool CCP-2 and I have a mid-80s World Sport. This is EXACTLY the tool you need. Just buy it. Once you do you will be amazed at the ease with which it works.



The outer threaded piece with the hex unscrews completely from the rest of the tool. Assuming the plastic caps are completely removed from the crank, you just thread in the outer piece with the threads, then just thread in the rest of the tool and wind it up until it pops off. It is so exactly the tool for the job, you'll kick yourself for not having it once you see how well it works.

We really should buy one of those. The handle doesn't seem like it's long enough.

Be very very careful when you thread it into an alu crank. It is very easy to kill the fine thread with this tool.

That's why I suggested taking it off the main part of the tool first. It's easier to thread in a small piece than a large piece with an offset handle.

I just noticed that. It can't be a very heavy duty puller if all you have to turn the forcing screw is a t-handle. I've use BIG breaker bars on the end of my puller (Craftsmen version of the one I posted above) without issue (press-fit crank pulleys on American cars are a PITA). I like the concept of the lockout feature for the arms but I wonder how effective it really is especially as the load increases.