choddo

Sounds like maybe it wasn’t screwed in far enough? Which might mean you can get hold of some threading further in. Did you unwind the extractor bolt all the way at the start?

I’m slightly confused - the bike is old enough to have worn out the chainrings and the arm to have seized on to the crank spindle but too new to be in a database?

what are you trying to get from the database? Details of which bottom bracket it uses? Don’t know if you’re going to be able to remove that with the arm still in the way.

JoeTBM 

There are other methods that can be used top remove the crank arm if the threads are stripped. Google "remove stripped bike crank arm" also search for threads on here as well.

choddo

Oh - did you remove the crank bolt?

base2 

Unfortunately pulling all the threads out of the crank arm is a sort of common occurrence. It has to do with manufacturing tolerances and how stuck the crank arm was on the bottom bracket spindle taper. Whether or not any grease was used on the taper is a huge contributing factor. Grease will prevent galvanic corrosion between the steel spindle and the aluminum crank arm. In addition to this, the diameter of the threads the puller threads in to determine the quality of the interface between the tool and the part. Combine that with the quality of the aluminum casting the threads are cut and it will determine just how hard you can pull before failure.

A Schwinn Sidewinder, like all bikes made by Pacific Cycles is made to a price point. Unfortunately this also means pot metal, low manufacturing tolerances, and lack of grease throughout. A trifecta for problems. Fortunately, this also means that repair items are cheap, if you can steel yourself against all the hassle. Any bike shop will have a small selection of replacement crank arms hanging on a hook in the back room for situations like yours. Expect $15-30 or so.

As far as removing the stuck on arm, I've decided that the most effective method for removal is simply a hack saw with a good sharp blade. The aluminum, especially the low grade stuff gives way quite readily and it's about a 15 minute job to cut down in line coaxial with the spindle and along the taper. When your arm gets tired drive in a wedge to break off the rest of the uncut remaining at the fat end of the base. Then lever the arm off the spindle sideways. With only 3 of the four sides remaining with the spindle, the crank arm levers off quite easily.

Trakhak

Many people have stripped threads with a crank extractor as a consequence of forgetting to remove the crank bolt washer before threading in the extractor.

Kontact 

Or not tightening the extractor head into the crank threads with a wrench.

Heat88

No, it was in far enough. Someone else here
suggested that it happened because the arm is made of aluminum.


If I had to get a a new crankshaft, maybe that would help with identifying the specs for it.

Heat88

https://schwinnbikeforum. com/SLDB/serial.htm Maybe that page just hasn't been updated in a really long tome.

Heat88

I already found this video:

Heat88

Yes

Heat88

I already have a new crankset bought, and was intending on installing it, so that's not an issue.

If all other avenues are exhausted, I'll probably do that.

Heat88

There are no washers in my case.

Heat88

No. It was in far enough. Aluminum crank arm vs steel puller was probably the cause. I actually didn't realize it was aluminum.

Heat88

I don't understand why anybody still has to do anything experimental with the basic design of deep sea subs anymore. Somebody figured it out 64 years ago when they built one that was able to go down to the Mariana Trench which is the deepest place in all of the oceans and 3 times deeper than where the Titanic is. There should be deep sea tours by now.

mpetry912 

Heat88

just loosent the bolt, ride around the block 2-3 times and when you come back the arm should be loose enough to pull off easily

/markp

choddo

I think if you try scaling up the Trieste’s passenger sphere, and the air inside it, you run into a whole new world of engineering challenges.

Kontact 

Virtually all square taper cranks have aluminum threads. But it isn't a question of far enough, but tightening torque so all the threads share the load.

Your response leads me to believe you didn't tighten it with a wrench, which will lead to the threads being unevenly loaded so they tear out one at a time, kind of like breaking a stack of spaced boards with a karate chop.

In the decades that I have been a mechanic, I only damaged one crank with a puller - when I didn't tighten it down with a wrench. That was in 1990.

base2 

You mean like this one?








I was fortunate enough to be assigned to repair this thing on the ship that carries Alvin. https://m.youtube.com/watch?v=HMSkEz...ature=youtu.be

The problem is the way the forces scale. There is zero original components on this thing and it has been rebuilt a couple of times over. Here is a good history: https://www.whoi.edu/what-we-do/expl...tory-of-alvin/

JoeTBM 

well that was one of the worse recommendations I have even seen.

Search on the site about using a "pickle fork" or a set of 'jacob's wedges". We have used both methods in our shop with great success and requires minimal effort.

choddo

That guy reminded me of Vinz Clortho, keymaster of Gozer, Volguus Zildrohoar, Lord of the Seboullia.

Heat88

I used a crescent wrench.

Kontact 

And did you use the wrench to make it firmly tight?

Trakhak

My guess, in the absence of clarification, is that he threaded the puller in by hand and then used the Crescent wrench to turn the puller's thrust bolt, inadvertently stripping the crank's threads.

That, or he accidentally cross-threaded the crank's threads when he threaded in the puller.

Or a previous removal attempt left the crank arm threads in a damaged state.

Can't think of any other possibilities offhand.

Heat88

Which part is the thrust bolt? The black part or the other part? And its not the crank. Its the pedal arm. how did that strip anything? I'm confused.

Kontact 

The thrust bolt is the other half of the extractor tool. It's the inner part you turn to actually push against the spindle to force the crank off.