Square taper crank stuck on spindle, crank removal threads stripped
 

So, I'm fixing up an old, not at all special, early 80s Schwinn LeTour for a friend of my wife's (it will be new to her...so no worries about screwing up someone else's bike). I was trying to remove the drive side crank (square taper, swaged, Sugino crank otherwise without a model designation) using my crank removal tool (Park CWP-7). I discovered the crank is very well attached, and I just ended removing all (yes, all) of the threads used by the crank removal tool (non-drive side removed just fine). So, the crank is stuck on the bike and I want it off.

Even though there isn't much space, I was able to get a cheap headset wrench around the fixed-cup on the drive side...but it is simply too tight/rusted-in to remove, at least with that wrench and the limited space I have with the crank in the way.

So, I'm wondering about my options. I don't care about saving the spindle, crank, etc. if I can't - as I have others that would work fine and, well, I'm not going to re-use a crank without extraction threads. However, I'm hoping there is something I can do at home without taking it to the LBS, where, I imagine they'd just cut through the whole thing.

I have a pretty good set of bike tools but a very limited set of power tools..a drill and a dremel tool. Any ideas or things I missed?

I used a set of Jacobs Chuck removal wedges. They're made for a similar job, namely removing a drill chuck from the tapered spindle. You gently tap them in behind the crank from both sides and they ease it off 100% of the time with no damage. What's nice is that they're cheaper than most bicycle crank pullers.

Once you use them and see how well they work, you'll have no qualms about reusing that crank and BB if they're otherwise OK, and may never go back to bike crank pullers again.

One note, I forgot the right size, so you have to ask for one with the right slot to clear a 9/16" spindle.

Pickle fork? Be sure to protect any paint/metal you want to preserve...

Put the non-drive crank back on. Leave the bolt loose on the crank that's stuck. Grind up a hill carefully in too high a gear -- without the bolt keeping it in place, the soft aluminum crank will quickly squirm loose on the steel taper. Quickly enough that you need to be careful or you'll lose your teeth on the handlebars. I've never had a stuck crank that took more than maybe 20 hard pedal strokes to work loose when the bolt is backed off, your mileage may vary depending on how hard you're pedaling.

Note this ruins the crank taper, it will never install securely again.

If you want to save a valuable crank in this situation, I use a piloted bottoming tap to enlarge the threads to 23mm puller threads, the larger size on the side of the crank puller you never use unless you have old TA cranks.

I have heard to use the pedal hard while crank arm bolt is loose trick before but how come no one ever suggests leaving the bolt in place but loosened about say 5 or 6 turns? Just enough to allow the crank to break free but hopefully not fall off completely causing the rider to crash forward, cracking a few teeth, and then just falling down. :)

This is not a hard and fast rule.

It can ruin the crank arm, but often it does not.

automotive V-belt pulley pullers reach behind the crank, then the screw pushes down on the end.

but they are 3 armed things, most bikes have 5 armed spiders .. or 4.

Just going to toss in a reminder that the fixed cup is reverse threaded on english bottom brackets.

If the bolt is loose enough for the crank to squirm loose, it's generally loose enough for the crank to deform on te spindle. If you pay attention you won't hurt yourself, but not knowing the mechanical aptitude of the OP, I figure it's prudent to warn of what can happen. (same with wrecking the crank -- not inevitable, but common enough that I wouldn't suggest this method on a crank you want to reuse.)

Crank's already shot. At least it better be, otherwise we'll be right back here next time he wants it off.

The chuck removal wedges are a good idea, but they are expensive for a complete set. A stick non-drive side crank comes off easily with an automotive gear puller, but not so for the drive side (the spider is usually in the way of the puller "fingers"). If only the drive side crank is stuck you can remove the non-drive crank and pull the axle out of the BB and then you can tap the drive crank off of the spindle while it's on the bench.

$6.95 for a pair is expensive? You don't need a set, just one pair in the right size. years ago, I used to sell them to bike shops for $5.00/pr.

reading this thread reminded me of this blog posting
http://thegoldenwrench.blogspot.ca/2...xtraction.html
but this is much more expensive than the wedges

Had a similar problem... solved it using a combination of heat and the modified gear puller pictured below. We heated the NDS crank arm where it attached to the spindle (propane torch, be careful with the paint on the bike), then applied the gear puller. My mechanic friend used a special pair of clamping Vice Grips to keep the gear puller attached to the crank arm. I think you could still do the same thing on the drive side; it might even be easier.

https://lh5.googleusercontent.com/-z...2520Puller.jpg

Thanks for all the advice everyone. Since I waited to remove the crank as the last step in the complete disassembly of the bike, I didn't really want to put it back together again to ride around for removal. I decided to pick up a cheap pickle fork at the local auto parts store (little under $10) and spent a good 30-40 minutes (about 29-39 more minutes than I initially thought it would take) hammering away. It still took a lot of hammering, getting it jammed in there, rocking it a bit, moving it around the crank, repeating, etc. I didn't even have a chance with the regular crank puller. I would be nervous doing this on a pricier bike...but for this Schwinn, I was okay with the risk. I got it off the bike. Bike is fine, and I have a different crank to put on it.

Old thread, but it helped a bit. I got the non-drive arm and its cup off, but the BB wouldn't come out from the crank side. I snapped off the head on my cheap ebay puller. Went to the bike shop and got a miserable Doctor Gear tool. Had to strap a bar to it to get any torque. It started to strip the threads. Decided to bring out the sawzall as I was not re-using any of the parts.

Cut one side down to the axle. Crank didn't move. Cut the other side. Crank was like a rock. Took blow after blow. Then I started cutting the gear rings. After the second ring was cut, the tension released and it popped right off. Whew.

http://bikeforums.net/attachment.php...hmentid=517706

I had one like that. I wanted the cranks so I was able to use an angle grinder on the spindle between the DS crank and the shell. Even after that I put the crank (with the remaining spindle in it) on top of my vice I had to beat the hell out of the spindle to finally get it to pop out.

scott s.
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a late comment: lots of people mention hammering - i saw a youtube vid where the guy just hammered the crank off. my old man taught me never to hammer anything where the bearings end up taking the impact - unless you want to chuck away the bearings. i've used heat on the cranks and the aluminium/steel thing worked. but now i've got the same situation and heat isnt working. inclined to try the riding technique - dont see how and ally crank can damage a steel spindle but.

common bearing balls are cheap, so can a loose ball BB be cheap the crankset he destroyed might be $40. all riveted together .