Stuck in low gear.

[Will N]

I think it is possible for the pedal to go over-center if the bands are too worn and the pedal isn't adjusted to take up the wear. The edge of the pedal is configured like a ramp, and as you depress the pedal the ramp rotates and makes the pedal shaft move to the left, pulling on the band. You can go past the top of the ramp and down the other side which will make the pedal stick.