I am trying to take the sprocket wheel off an old Spiegel Airman bicycle. I know I have to unscrew the pedal arms from each other, but I don't know if the threads are right or left handed. The nut opposite the sprocket wheel was left handed. Things are pretty rusted and I have turned really hard to separate the 2 sides, assuming it was right handed, but it wouldn't budge. I am wondering if the threads may be left handed.