There is another way to remove cranks that have stripped extractor threads that uses the spindle threads, a crank bolt, a piece of pipe or tubing cut 1/2" longer than the exposed spindle, and another small split spacer to put between the cup and stripped arm needing help.. To remove a right crank, you make up a split aluminum or hardwood spacer to fit behind the crank between the fixed cup and the crank.. A couple wraps of electrical tape or bailing wire will do to hold it in place and not spread under load. Next you remove the lockring from the left side and unscrew the bb cup slightly to give you drawing room between the left bearings and the race on the adj cup. An old pair of steel or aluminum bars make a good donor source for tubing. You need to cut it of square and about 1/2" longer than the exposed spindle.. A thick washer with 3/8" hole covers the end of the pipe and allows you to use the crank bolt to extract. Crank washers like Sugino with smaller holes work well without distorting, but I found some thicker ones at my local hardware store. As you tighten the crank bolt and draw off the spindle, you loosen the adjustable cup as you go to maintain space between the race on the spindle the bearings and the race on the adjusting cup. If you don't loosen the cup before you start..you'l crank in vain.. Or you can remove the bearing from the adjustable cup and set the cup where it gives you 1/2 " of drawing room. This method works great and doesn't damage the crank. You can reverse the process to remove a left crank if you can get the fixed cup loose. If you can't budge the fixed cup, you can unscrew the adjustable cup to give you room to draw the spindle. I've used this method many times with sucess. Especially on SR cranks! Cheap cast threads!!!!! Good Luck!
Paul Brown
Cycle Dynamics
707 322-7208
Santa Rosa CA